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IN  MEMORIAM-^  s 


THE 

ARTIFICIAL    FEEDING 

OF 

INFANTS 


THE 

ARTIFICIAL   FEEDING 

OF 

INFANTS 


INCLUDING  A   CRITICAL   REVIEW  OF   THE 

RECENT  LITERATURE  OF  THE 

SUBJECT 


BY 

CHARLES  F.  JUDSON,  M.D. 

PHYSICIAN    TO    THE    MEDICAL    DISPENSARY    OF   THE    CHILDREN'S    HOSPITAL 
AND 

J.  CLAXTON  GITTINGS,  M.D. 

ASSISTANT  PHYSICIAN  TO  THE  MEDICAL  DISPENSARY  OF  THE  CHILDREN'S 
HOSPITAL 


PHILADELPHIA 

J.  B.   LIPPINCOTT   COMPANY 

1902 


o.r 


Copyright,  1902 
By  J.  B.  Lippincott  Company 


MINTED   BY  J.  B.  LIPPINCOTT   COMPANY,    PHILADELPHIA,    U.S.A. 


PREFACE. 

The  aim  of  this  work  is  to  place  before  the  medical  pro- 
fession a  thorough  and  reliable  account  of  the  principles  and 
methods  of  artificial  feeding  in  vogue  at  the  present  day. 
Much  valuable  material  (not  contained  in  the  average  text- 
book) has  been  collected,  representing  the  results  of  extended 
scientific  investigations.  The  substance  of  this  work  has  been 
gleaned  from  the  periodical  literature,  monographs,  and  text- 
books of  the  past  eight  years  (1894-1901),  so  that  this  treatise 
may  justly  claim  to  be  an  authoritative  statement  of  the  views 
of  the  leading  pediatrists  and  scientists  of  Europe  and  America 
on  the  subject  of  Artificial  Feeding  at  the  present  day.  Grate- 
ful acknowledgment  is  made  of  our  indebtedness  to  the  authors 
cited  for  their  readily  granted  permission  to  quote  from  their 
works;  especially  we  thank  Professor  A.  B.  Marfan,  of  Paris, 
Professor  Monti,  of  Vienna,  Dr.  Cautley,  of  London,  and  Mr. 
H.  Droop  Richmond,  chemist  of  the  Aylesbury  Dairy  Com- 
pany, whose  names  find  frequent  mention  throughout  the 
following  pages. 

It  is  inevitable  in  a  treatise  of  this  character  that  many 
repetitions  should  occur  and  that  many  conflicting  statements 
should  be  made.  Since  the  purpose  of  the  work  is  to  give 
a  clear,  impartial  statement  of  the  views  of  each  author,  de- 
tailed criticisms  of  their  methods  of  feeding  are  avoided ;  but 
it  has  been  the  authors'  aim  to  incorporate  in  the  concluding 
chapters  (XII.,  XIII.,  and  XIV.)  the  guiding  principles  which 

5 

39564U 


6      ,v  PREFACE. 

form  the  groundwork  of  all  methods  of  feeding.  An  attempt 
has  been  made  on  this  basis  to  construct  a  theory  of  infant 
feeding  which  shall  be  sufficiently  broad  in  its  scope  to  meet 
the  widely  varying  needs  of  different  infants,  the  cardinal 
principle  being  kept  in  mind  that  each  case  is  a  unit,  and  that 
we  must  carefully  adjust  the  diet  to  the  requirements  of  the 
individual  infant  if  we  wish  to  be  successful. 

The  management  of  lactation  (and  wet-nursing)  has  not 
been  considered,  since  it  does  not  directly  concern  the  purpose 
of  this  book. 

Professor  Henry  Leffmann  kindly  consented  to  review  the 
statements  relating  to  the  chemistry  of  milk  and  milk  products, 
and  Dr.  David  L.  Edsall  the  chapter  on  Metabolism. 

In  conclusion,  we  desire  to  thank  Dr.  Harvey  Shoemaker  for 
much  kind  advice,  Mr.  Walter  E.  Cuthbert  for  his  practical 
assistance,  and  our  publishers  for  their  courtesy  and  aid  in  the 
preparation  of  the  work. 


CONTENTS. 


CHAPTER  PAGE 

I.  Historical 9 

II.  Mother's  Milk 18 

III.  Cow's  Milk 44 

IV.  Digestion 61 

V.  Modern  Methods  of  Infant  Feeding 94 

VI.  Weaning I 167 

VII.  Care  of  the  Milk 179 

VIII.  Bacteriology 196 

IX.  Sterilization  and  Pasteurization 216 

X.  Weight  and  Growth — Metabolism   237 

XI.  The  Feeding  of  Premature  Infants 270 

XII.  Principles  of  Infant  Feeding 275 

XIII.  Methods  for  the  Home  Modification  of  Milk 296 

XIV.  Practical  Rules  for  Feeding 318 

XV.  Artificial  Foods  327 

Appendix  335 

Bibliography    345 

Index    355 


THE 

ARTIFICIAL    FEEDING 

OF 

INFANTS. 

CHAPTER    I. 
HISTORICAL. 

A  cursory  survey  of  earlier  publications  treating  of  the 
artificial  feeding  of  infants  shows  that  the  necessity  of  dilu- 
tion to  adapt  cow's  milk  to  the  infant's  powers  of  digestion 
was  recognized  as  far  back  as  the  middle  of  the  eighteenth 
century.  In  a  treatise  entitled  "  On  the  Eaising  of  Healthy 
Infants/'  published  by  J.  P.  Frank  in  1749,  we  read  that  Von 
Swieten,  Loseke,  and  Cosner  were  the  first  to  recommend  di- 
luted cow's  milk  for  infant  feeding;  they  advised  to  dilute 
from  two  to  five  times  with  water.7  Frank  advocated  dilution 
with  either  plain  water,  barley-,  wheat-,  or  oatmeal-water.7 

The  use  of  ass's  milk  and  of  animal  broths  seems  to  have 
found  early  recognition.  John  Armstrong,  in  "  An  Account 
of  the  Diseases  most  incident  to  Children,"  London,  1783, 
recommends  that  the  nursing  child  should  take,  in  addition 
to  the  breast,  pap  or  panada  made  from  bread-crumbs  boiled 
in  water  and  sweetened  with  sugar.  If  the  child  be  artificially 
fed  from  the  start,  it  should  have  "  cow's  milk  mixed  with  its 
victuals  as  often  as  possible  and  now  and  then  a  little  of  it 
alone  to  drink.  Ass's  milk  will  be  still  better."  If  the  milk 
disagrees,  animal  broths  should  be  given.  To  assist  teething 
and  promote  the  secretion  of  the  salivary  glands,  a  crust  of 

9 


10  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

bread  dipped  in  water  or  milk  should  be  given  to  the  child  to 
suck. 

The  next  advance  in  methods  of  feeding  among  English 
writers  is  to  be  found  in  John  Clarke's  "  Commentaries  on 
the  Diseases  of  Children/'  London,  1815.  This  author  was 
one  of  the  first  to  advocate  the  employment  of  cream  diluted 
with  starchy  decoctions;  he  also  seems  to  have  used  whey  as 
a  beverage.  To  quote  his  own  words :  "  Ass's  milk  is  the 
best  substitute  for  that  of  the  mother — cow's  milk  is  too  rich 
and  contains  too  much  oil  and  cheesy  matter.  The  latter  is, 
moreover,  formed  by  the  gastric  juice  in  the  stomach  into  a 
firm  curd,  which  is  not  digestible  by  the  stomach  of  an  infant. 
Diluting  it  with  water  does  not  entirely  prevent  this;  there- 
fore, when  ass's  milk  cannot  be  procured,  it  is  best  to  mix 
cow's  milk  previously  skimmed  with  two-thirds  or  three-fourths 
of  its  measure  of  gruel  made  from  pearl-barley,  grits,  or  arrow- 
root. When  so  mixed  it  does  not  become  hard  in  the  stomach, 
.  .  .  but  forms  a  thick  fluid.  As  a  child  advances  in  age 
the  proportions  of  milk  may  be  gradually  increased.  Where 
this  food  does  not  agree  with  the  child,  weak  mutton,  chicken, 
or  beef  broth,  clear  and  free  from  fat,  mixed  with  an  equal 
measure  of  the  mucilaginous  or  farinaceous  decoctions  above 
mentioned,  may  be  tried.  With  some  children,  when  no  form 
in  which  cow's  milk  can  be  given  will  agree,  the  stomach  will 
digest  farinaceous  decoctions  mixed  with  cream.  Solid  animal 
food  should  not  be  given  until  the  child  has  all  the  canine  teeth, 
and  then  in  small  quantities  and  only  once  a  day.  Water 
either  plain  or  with  toasted  bread  infused  into  it,  and  rennet 
whey,  are  the  best  beverages  for  children.  As  soon  as  a  child 
has  got  any  of  the  teeth  called  incisors,  solid  farinaceous  mat- 
ter boiled  in  water,  beaten  through  a  sieve  and  mixed  with  a 
small  quantity  of  milk,  may  be  employed,  and  then  for  the 
first  time  the  child  should  be  fed  by  hand.  When  the  molars 
or  grinding  teeth  have  protruded  through  the  gums,  the  child 
should  live  upon  farinaceous  matter,  mixed  with  milk  or  weak 


HISTORICAL.  1 1 

broth,  but  the  bread  need  not  be  beaten  through  a  sieve,  be- 
cause the  child  has  now  an  apparatus  for  grinding  it." 

The  directions  given  by  Dewees  for  the  preparation,  hand- 
ling, and  administration  of  an  infant's  food  are  very  similar 
to  those  in  vogue  at  the  present  day.  Dewees  recognized  the 
value  of  the  application  of  heat  to  prevent  decomposition  of 
the  milk,  but  advised  against  the  use  of  prolonged  heat  at  a 
temperature  at  or  above  boiling.  We  quote  from  the  fourth 
edition  of  his  work  on  Children's  Diseases,  Philadelphia,  1832 : 

"  Milk  should  be  diluted  one-third  with  water  and  loaf  sugar 
added  to  make  the  proportions  resemble  mother's  milk. 

"  I.  The  milk  should  be  pure,  not  skimmed  or  watered,  and 
used  as  soon  as  possible  after  milking. 

"II.  When  practicable,  use  milk  from  the  same  cow,  to 
avoid  variations. 

"  III.  Mix  sugar  and  water  just  before  giving,  to  avoid  fer- 
mentation. 

"IV.  Only  the  quantity  should  be  prepared  that  will  be 
used. 

"V.  Milk  should  be  heated  by  adding  hot  water  or  by  a 
sand-bath,  not  on  a  range. 

"  VI.  Milk  should  be  kept  in  the  coolest  possible  place. 

"VII.  It  should  be  rejected  if  acid.  Too  much  must  not 
be  given  at  once. 

"In  cool  weather,  after  the  fifth  month,  barley-,  rice-,  or 
gum-arabic-water  may  be  added  to  the  diet  if  desired,  also  a 
small  amount  of  arrowroot,  or  a  small  amount  of  some  animal 
juice  may  be  given  in  conjunction.  After  the  child  has  its 
molars,  the  diet  should  consist  principally  of  milk,  to  which 
grated  cracker,  well-baked  stale  bread,  rice  flour,  or  arrowroot 
may  be  added ;  occasionally,  animal  broths  may  be  used,  pref- 
erably beef,  mutton,  or  chicken.  After  the  eye-  and  stomach- 
teeth  have  erupted,  small  amounts  of  roasted  meats  may  be 
added  once  a  day.  Stale  bread  and  butter — the  latter  must  be 
of  good  quality — are  permissible  at  this  age.     Butter  is  not 


12  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

only  innocent  but  highly  useful;  the  use  of  potatoes  is  not 
recommended,  except  in  small  quantities  and  only  after  the 
ninth  month;  they  should  be  well  mashed  with  hot  milk,  but- 
ter, and  salt. 

"  I.  Never  put  a  second  supply  of  milk  upon  the  remains  of 
a  former,  unless  a  very  short  interval  has  elapsed  and  they  are 
of  the  same  making. 

"  II.  So  soon  as  a  child  has  taken  as  much  as  it  chooses,  or  as 
much  as  may  be  judged  proper  for  it,  let  the  bottle  be  emptied 
of  any  food  remaining  and  immediately  cleansed  by  hot  water. 

"  III.  When  well  cleansed  by  the  hot  water,  let  it  be  thrown 
into  and  kept  in  a  basin  of  cold  water  in  which  there  is  a  little 
soda  dissolved. 

"  IV.  Before  using  let  it  be  rinsed  with  clear  cold  water. 

"V.  Let  the  extremity  from  which  the  child  is  to  suck  be 
covered  with  a  heifer's  teat  in  preference  to  anything  else. 

"VI.  Let  not  the  teat  be  of  too  large  a  size,  nor  one  that 
will  permit  too  rapid  a  flow  of  the  food,  especially  for  a  very 
young  infant. 

"  Cow's  milk  contains  more  cheesy  matter,  and  is  on  this 
account  of  more  difficult  assimilation;  hence  it  is  frequently 
thrown  up  in  the  form  of  a  hard  curd.  Only  so  much  milk 
must  be  taken  into  the  stomach  as  the  infant  can  assimilate 
and  digest  in  due  time ;  the  latter  may  be  fixed  at  three  to  four 
hours. 

"  Upon  no  occasion,  when  the  child  is  in  health,  will  the 
milk  require  boiling,  for  this  takes  from  the  milk  some  of  its 
best  qualities.  In  hot  weather,  it  is  true,  the  tendency  to 
decomposition  is  diminished  by  boiling  the  milk,  but  as  all  the 
advantages  which  result  from  this  process  can  be  procured 
without  its  being  absolutely  boiled,  it  should  never  be  had 
recourse  to. 

"It  is  every  way  sufficient  for  the  purpose  of  preservation 
that  the  milk  be  put  closely  covered  over  a  hot  fire  and  brought 
quickly  to  the  boiling  point;    so  soon  as  this  is  perceived,  it 


HISTORICAL.  13 

should  be  removed  and  cooled  as  speedily  as  possible.  By  this 
plan  we  prevent  in  great  part  the  formation  of  that  strong 
pellicle  which  is  always  observed  on  the  top  of  boiled  milk,  and 
by  which  the  milk  is  deprived  of  one  of  its  most  valuable 
parts. 

"  For  a  certain  period  after  each  meal  rest  is  essential  to 
digestion,  as  exercise  is  important  at  other  times  for  the  gen- 
eral promotion  of  health. 

"  The  preposterous  and  highly  injurious  practice  of  '  jolting' 
should  be  absolutely  prohibited. 

"  The  bottle  must  not  become  the  plaything  of  the  child. 

"  The  child  should  not  receive  its  nourishment  while  lying ; 
it  should  be  raised. 

"When  the  child  ceases  to  extract  milk  from  the  bottle, 
and  this  be  restored  to  the  child,  who  again  refuses  to  take  it, 
let  the  child  on  no  account  be  urged  to  swallow  more  than 
nature  seems  to  demand.  This  also  holds  good  when  the  child 
is  at  the  breast/' 
)  Carl  Gerhardt  59  in  1871  recommended  dilutions  of  cow's 
milk  for  different  ages  to  be  prepared  in  the  following  man- 
ner :  for  the  first  eight  days  one  part  of  milk  to  three  parts  of 
water,  from  that  time  up  to  three  months  one  to  two,  from 
four  to  nine  months  equal  parts  of  milk  and  water,  and  after 
the  ninth  month  pure  milk.  After  the  sixth  month  meat  broth 
can  be  used  as  a  diluent. 
/  John  Forsyth  Meigs,  of  Philadelphia,  a  renowned  pedi- 
atrist  in  his  day,  was  the  originator  of  a  mixture  of  milk,  cream, 
gelatin,  and  arrowroot-water  (see  his  text-book,  second  edition, 
1853)  which  gave  very  satisfactory  results  for  the  feeding  both 
of  sick  and  healthy  infants.  He  advised  for  a  child  of  good 
health  under  one  month  from  three  to  four  ounces  of  milk, 
one-half  to  one  ounce  of  cream,  and  half  a  pint  of  arrowroot- 
water  (containing  one  drachm  of  arrowroot).  For  older  chil- 
dren the  quantity  of  milk  was  to  be  increased  to  one-half  or 
two-thirds  of  the  total  mixture,  and  the  cream  raised  to  two 


14  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

ounces.  During  the  seventies  he  advocated  the  use  of  a  mixture 
of  equal  parts  of  milk,  cream,  lime-water,  and  arrowroot-water, 

/sweetened  with  a  little  sugar.  In  this  preparation  the  princi- 
ples governing  modification  of  milk  for  infant  feeding  are 
correctly  outlined,  and  it  is  not  too  much  to  say  that  all  the 
later  advances  in  method  start  from  this  fountain-head.  The 
elder  Meigs  recognized  the  importance  of  adding  cream  to  make 
up  the  deficiency  in  fat  of  his  mixture,  and  it  was  due  to  his 
incentive  that  the  younger  Meigs  pursued  the  question  further, 
with  the  result  of  determining  the  proportions  of  the  proteids 
in  mother's  milk,  thus  placing  the  question  of  dilution  on  a 
scientific  basis. 

The  subject  of  the  percentage  of  proteids  in  mother's  milk 
was  a  mooted  one  until  recent  years.  Chemical  researches  had 
given  varying  results,  the  methods  employed  being  generally 
.  inaccurate.  During  the  fifties  and  sixties  the  tendency  was  to 
I  accept  the  figures  of  Vernois  and  Becquerel,  who  had  found 
a  casein  percentage  of  3.924.  Eegnault,  Simon,  and  Clemm 
obtained  similar  results,  but  Henri  and  Chevalier  had  found 
an  average  of  1.52  per  cent.,  l'Heritier  1.3  per  cent.,  and 
Quevenne  1.05  per  cent.  The  latter  figures  were  not,  however, 
generally  considered  reliable,  since  they  were  based  on  a  small 
number  of  cases  only  ("  Milk  Analysis  and  Infant  Feeding," 
Meigs).  Brunner,  as  far  back  as  1873,  had  published  the  re- 
sults of  his  analyses  of  human  milk,  which  gave  him  an  aver- 
age of  from  1.3  to  1.4  per  cent,  casein  (Pfliiger's  Archiv 
fur  Physiologie,  Bd.  vii.).  On  empirical  grounds  Biedert  had 
arrived  at  the  conclusion  that  the  proper  proportion  of  cow's 
milk  casein  in  an  infant's  food  was  one  per  cent.,  and  had 
formulated  his  Cream  Mixture  accordingly.  Biedert's  article 
in  Virchow's  Archiv  for  1874  advised  the  use  of  a  mixture 
of  cream  diluted  four  times  with  water,  to  which  milk-sugar 
was  to  be  added.  He  concluded  from  numerous  experiments 
on  the  coagulability  and  digestibility  of  human  and  cow's  milk 
that  they  varied  in  two  important  points:    "first,  in  the  dif- 


HISTORICAL.  15 

ferent  amounts  of  casein  contained;  second,  in  the  absolute 
chemical  differences  of  the  two  sorts  of  casein."  160  Biedert's 
Cream  Mixture  contained  one  per  cent,  casein,  2.4  per  cent, 
fat,  and  3.6  per  cent,  sugar  of  milk. 

The  question  of  the  percentage  of  casein  in  mother's  milk 
was  still  unsettled  in  1882,  when  Arthur  V.  Meigs  an- 
nounced the  results  of  his  investigations,  which  determined  the 
amount  of  proteids  to  be  one  per  cent,  (approximately)  and 
the  sugar  seven  per  cent.  These  figures  were  based  on  analyses 
of  the  milk  of  forty-three  women,  the  samples  being  obtained 
at  different  times  and  under  varying  circumstances.  Starting 
from  the  assumption  that  cow's  milk  must  be  diluted  suffi- 
ciently to  reduce  the  casein  percentage  to  that  of  human  milk, 
Meigs  devised  the  following  preparation,  commonly  known  as 
"the  Meigs  Mixture,"  which,  in  his  opinion,  meets  the  re- 
quirements of  infant  feeding. 

173  «  There  must  be  obtained  a  quart  of  good  fresh  milk ; 
not  too  rich  and  not  poor,  average  milk  is  best;  this  is  placed 
in  a  high  pitcher  or  other  vessel  and  is  allowed  to  stand  in  a 
cool  place  for  three  hours.  The  upper  half  or  pint  is  then 
poured  off,  care  being  taken  not  to  shake  the  vessel,  and  this 
upper  pint,  of  weak  cream,  is  to  be  kept  for  the  use  of  the 
infant.  The  other  half  of  the  quart,  which  is  skimmed  milk, 
may  be  sent  to  the  kitchen.  There  must  also  be  made  a  solu- 
tion of  milk-sugar  of  the  proportion  of  eighteen  drachms  to 
the  pint  of  water.  It  is  best  to  weigh  the  sugar,  or  to  have 
an  apothecary  prepare  a  number  of  packages  each  containing 
eighteen  drachms  of  milk-sugar.  A  wide-mouthed  pint  bottle 
should  be  provided,  into  which  may  be  put  eighteen  drachms 
of  milk-sugar  and  one  pint  of  water.  By  having  a  wide- 
mouthed  pint  bottle  there  is  no  need  for  any  other  measure, 
and  the  sugar  in  bulk  is  more  easily  put  into  such  a  bottle 
than  into  an  ordinary  one  with  a  narrow  neck.  The  sugar- 
water  must  be  kept  in  a  place  that  is  not  too  hot,  nor  should 
it  be  kept  in  a  refrigerator,  as  great  cold  precipitates  the  sugar 


16  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

and  heat  causes  it  to  ferment.  In  hot  weather  the  sugar  solu- 
tion should  be  examined  from  time  to  time,  and  if  it  sours 
must  be  thrown  out  and  prepared  afresh.  Having  the  milk 
and  the  sugar-water  ready,  only  one  other  ingredient  is  re- 
quired, lime-water-. 

"  When  the  food  is  to  be  used  there  must  be  taken  of  the 
weak  cream  (the  upper  pint  which  was  poured  off  and  retained) 
three  tablespoonfuls,  of  the  lime-water  two  tablespoonfuls,  and 
of  the  sugar-water  three  tablespoonfuls.  These  substances 
together  are  placed  in  a  feeding-bottle  and  warmed  to  the 
degree  which  may  be  desirable;  the  food  is  then  ready  for 
use. 

"An  infant  two  days  old  should  take  only  about  half  an 
ounce  of  nourishment  at  a  feeding,  and  it  will  take  this  amount 
seven  or  eight  times  each  day;  if  it  sleeps  naturally,  it  is  not 
possible  to  feed  every  two  hours,  which  would  make  twelve 
feedings  per  day.  The  proper  quantity,  therefore,  for  a  two- 
days-old  child  is  between  three  and  four  ounces. 

"  The  daily  amount  required  will  gradually  increase,  until 
at  the  end  of  twenty-one  days  it  will  be  found  that  the  infant 
is  taking  about  two  and  a  half  ounces  at  a  time,  and  still  about 
seven  or  eight  feedings  in  each  day,  making  a  total  of  from 
seventeen  to  twenty  ounces.  When  the  sixth  week  has  been 
reached,  about  four  ounces  will  be  taken  at  a  time,  making  a 
total  quantity  of  nearly  thirty-two  ounces.  These  estimates 
of  the  amount  of  food  for  infants  during  the  first  few  weeks 
of  life  may  possibly  be  a  little  too  high,  but  they  will  not  be 
found  to  vary  much  from  what  babies  should  have  at  that 
period  of  life.  .  .  .  Generally  a  baby  should  not  be  urged  to 
take  more  than  it  wants,  unless  it  is  very  indifferent  to  food 
and  takes  much  less  than  the  quantities  above  mentioned. 

"  After  the  first  six  weeks  it  will  be  found  that  there  is  a 
natural  desire  for  an  increased  quantity  of  food,  just  as  there 
was  in  the  earlier  period.  The  amount  taken  by  a  healthy 
infant  will  increase  to  six  or  eight  ounces  at  each  feeding, 


HISTORICAL.  17 

but  generally  the  number  of  daily  feedings  will  grow  less.  A 
very  young  infant  will  require  to  be  fed  seven  or  eight  times 
a  day,  but  one  of  from  four  to  six  months  will  only  take  nour- 
ishment from  five  to  seven  times  a  day.  The  quantity  taken 
will  be  found  to  vary  between  somewhat  less  than  two  pints 
and  three  pints.  The  food,  therefore,  is  to  be  increased  in 
amount,  but  continued  always  of  the  same  strength  until  an 
infant  is  from  six  to  nine  months  of  age." 

Meigs  has  never  been  an  advocate  of  sterilization  under  ordi- 
nary circumstances.  "  It  certainly  must  alter  the  milk  to  be 
cooked,  and  sterilization  is  cooking,  whether  the  heat  applied 
be  of  high  or  only  of  moderate  degree.  It  seems  better  and 
more  natural  to  see  that  the  milk  is  pure  and  free  from  all 
contaminations,  in  the  first  place,  than  to  purify  by  steriliza- 
tion a  milk  which  is  supposed  to  be  contaminated,  and  then 
use  it  to  feed  babies.  The  field  of  usefulness  of  the  process 
of  sterilization  is  probably  to  be  found  in  cases  where  it  is 
impossible  to  secure  pure  milk,  but  as  to  using  it  as  a  matter 
of  general  application  it  is  not  to  be  recommended." 

During  an  experience  of  fourteen  years  Meigs  has  used  this 
food  with  great  success.  He  estimates  its  composition  as  fol- 
lows: 

Per  cent. 

Water 87.639 

Fat 4.765 

Casein 1.115 

Sugar 6.264 

Salts 0.217 

100.000 


CHAPTER    II. 

MOTHER'S  MILK. 

Since  mother's  milk  is  universally  recognized  as  the  stand- 
ard which  should  be  imitated  in  the  artificial  feeding  of  in- 
fants, it  will  be  the  object  of  this  chapter  to  give  a  succinct 
account  of  its  composition  and  characteristics.  No  attempt 
will  be  made  to  discuss  the  physiology  or  the  management  of 
lactation,  since  the  purpose  of  this  work  is  to  discuss  the 
principles  governing  the  artificial  feeding  of  infants. 

Description. 

Mother's  milk  is  the  secretion  of  the  mammary  gland,  and 
consists  of  an  emulsion  of  small  fat-droplets  in  which  salts, 
sugar,  and  proteids  are  held  in  solution.  At  the  height  of 
lactation  it  is  bluish-white  and  semi-transparent,  of  sweetish 
taste,  odorless,  and  has  a  specific  gravity  of  from  1026  to  1036 
(Monti). 

According  to  Leeds,166  the  color  of  milk,  which  may  be 
chalky-white,  bluish-white,  yellowish-white,  or  yellow,  is  no 
indication  of  its  composition.  A  chalky  looking  specimen  may 
be  rich  in  fat  and  a  yellow  sample  poor  in  that  constituent. 
Mother's  milk  has  rarely  a  sweet  taste;  more  often  it  is  saline 
and  of  a  somewhat  disagreeable  animal  odor.  Its  consistence 
is  much  thinner  and  more  watery  than  cow's  milk. 

Specific  Gravity. 

Adriance 1030  average 

Kichmond 1030-1031  average 

Holt 1029-1032 

Monti 1030-1034 

18 


MOTHER'S   MILK.  19 

Variations. 

Johannessen 1025-1036 

Leeds 1026-1035.3 

Adriance 1017-1036 

An  increase  of  the  fat  lowers  the  specific  gravity,  a  decrease 
raises  it.  The  proteids  and  other  solids  have  a  reverse  effect, 
while  the  salts  are  too  insignificant  to  affect  it  one  way  or 
the  other.  As  the  sugar  varies  so  slightly,  it  may  be  considered 
that,  for  clinical  purposes,  the  specific  gravity  is  modified  solely 
by  the  fat  and  the  proteids  (Adriance69). 

In  Monti's  experience,  "breast-milk  which  has  a  specific 
gravity  of  1030  to  1035  and  at  the  same  time  a  fat  content 
of  three  to  five  per  cent., — that  is,  in  which  the  height  of 
the  specific  gravity  corresponds  with  that  of  the  fat  per- 
centage,— and  in  which  only  slight  changes  in  these  factors 
occur  during  nursing,  may  be  considered  a  good  one."  Low 
fat  averages  (from  one  to  two  per  cent.)  and  low  specific 
gravity  (1026  to  1029)  are  found  associated  usually  in  the 
milk  of  anaemic,  poorly  nourished  women.  In  those  cases 
in  which  the  woman's  milk  shows  a  high  specific  gravity  and 
a  low  or  subnormal  fat  content,  the  infants  do  not  thrive,  and 
such  a  milk  must  be  considered  to  possess  less  nutritive  value. 
The  only  sure  test,  however,  is  the  child's  weight. 

Estimation  of  the  Proteids.     (Holt's  Method.) 

"  In  estimating  the  proteids  certain  suppositions  must  and 
can  be  fairly  accepted. 

"  I.  Supposing  the  proteids  to  remain  unaltered ;  if  the  per- 
centage of  fat  be  low,  the  specific  gravity  will  be  high;  but 
if  high,  the  specific  gravity  will  be  low. 

"  II.  Supposing  the  fat  to  remain  unaltered ;  if  the  percent- 
age of  the  proteids  be  high,  the  specific  gravity  will  be  high; 
but  if  the  percentage  of  the  proteids  be  low,  the  specific  gravity 
will  be  low.    If,  therefore,  the  fat  and  the  specific  gravity  be 


20  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

known,   any   considerable   variation   in   the   proteids   may   be 
estimated  by  the  following  data: 

Data.  Conclusion. 

Percentage  of  cream.  Specific  gravity.  Amount  of  proteids. 

High,—  e.g.,  from  8-10  High,  1033-1034  High  percentage 

Low,—  e.g.,   from  3-4  High,  1033-1034  Nearly  normal 

High  Low,    1027-1030  Normal 

Low  Low,    1027-1030  Deficient" 

Holt  asserts  that  the  conclusions  drawn  from  this  mode  of 
examination  are  as  exact  as  those  obtained  by  the  ordinary 
examinations  of  urine. 

H.  Droop  Eichmond  considers  that  "  Holt's  method  is  based 
on  a  fallacy/'  and  that  the  results  obtained  with  it  are,  on  the 
whole,  unsatisfactory. 

Eeaction. — Authorities  are  practically  agreed  that  the  re- 
action of  normal  mother's  milk  is  uniformly  alkaline. 

Colostrum. 

Marfan.105  Colostrum  is  secreted  by  the  mammary  gland 
towards  the  end  of  pregnancy.  It  is  a  grayish-yellow  fluid, 
of  serous  consistence  and  slightly  turbid,  containing  streaks 
of  deep  yellow.  Its  reaction  is  alkaline  and  its  density  from 
1046  to  1065. 

Microscopically,  there  are  found:  (a)  fat-droplets,  some 
like  those  of  normal  milk  and  others  smaller,  poorly  formed, 
and  often  agglutinated,  which  denote  the  imperfection  of  the 
milk  secretion;  (b)  leucocytes,  some  of  which  contain  fatty 
detritus;  (c)  colostrum  corpuscles,  large  spherical  bodies, 
consisting  of  fatty  detritus  surrounded  by  a  membranous  en- 
velope, and  often  showing  amoeboid  movements. 

The  first  day  after  birth  the  secretion  of  the  mammary  gland 
contains  many  colostrum  corpuscles  and  fat-globules  of  un- 
equal size.    With  the  appearance  of  milk  on  the  third  day  the 


MOTHER'S   MILK. 


21 


colostrum  bodies  become  less  numerous,  but  the  secretion  still 
has  a  yellowish  color.  On  the  sixth  day  there  are  many  fat- 
globules  which  are  less  unequal  in  size,  and  the  colostrum  cor- 
puscles diminish  further  in  number.  After  the  fifteenth  day, 
as  a  rule,  we  find  no  colostrum  corpuscles;  the  milk  is  per- 
fectly white  and  normal  in  appearance.  The  fat-globules  tend 
to  become  more  nearly  equal  in  size,  but  vary  in  different  sub- 
jects, however,  during  lactation. 

Monti  "  states  that  the  colostrum  corpuscles  are  usually 
present  for  about  one  week  after  labor,  and  that  any  consider- 
able quantity  at  a  later  period  denotes  either  disease  of  the 
mother  or  pregnancy.  Jacobi 76  calls  attention  to  the  fact  that 
excessive  proteids  are  apt  to  cause  gastro-intestinal  symptoms 
during  the  colostrum  period,  particularly  after  premature  con- 
finement. 

Adriance  4  considers  that  the  colostrum  period  covers  the 
first  two  weeks  of  life.  During  this  time  we  not  infrequently 
find  the  fat  percentage  either  very  low  or  very  high.  The 
sugar  content  is  lower  than  at  any  other  time,  but  rises  rapidly, 
ranging  from  5.80  per  cent,  on  the  second  day  to  6.63  per 
cent,  on  the  fourteenth  day.  The  proteids  pursue  a  contrary 
course,  falling  from  2.77  per  cent,  on  the  second  day  to  1.70 
per  cent,  on  the  fourteenth  day.  The  ash,  like  the  proteids, 
is  higher  at  this  period  than  at  any  other.  Examples  of  colos- 
trum milk  are  cited  to  show  the  changes  during  the  first  part 
of  lactation. 


Mother — twenty 
years. 

Three             Six 
days.            days. 

Mother— nineteen 

YEARS. 

Two              Ten 
days.            days. 

Mother- 
three 

Six 
days. 

—TWENTY- 
YEARS. 

One  month, 

seventeen 

days. 

Fat 

Per  cent. 

...     4.52 

Per  cent. 

2.80 

Per  cent. 
3.77 

Per  cent. 

2.64 

Per  cent. 

4.30 

Per  cent. 

4.08 

Sugar  

. . .     5.86 

6.83 

5.39 

6.62 

5.38 

6.91 

Proteids  . . . 

...     2.37 

2.13 

3.31 

1.70 

2.79 

1.44 

Salts 

. . .     0.26 

0.25 

0.27 

0.23 

0.23 

0.19 

22  THE  ARTIFICIAL   FEEDING   OF   INFANTS. 

Woodward/49  in  the  Journal  of  Experimental  Medicine, 
March,  1897,  reports  the  results  of  the  examination  of  six 
cases  of  colostrum  milk  at  the  Pepper  Clinical  Laboratory. 
He  found  the  color  yellow,  the  reaction  alkaline,  and  the  specific 
gravity  from  1024  to  1034,  depending  on  the  amount  of  fat 
present,  which  varied  from  two  to  5.3  per  cent.  The  proteids 
ranged  from  1.64  to  2.22  per  cent,  and  the  ash  from  0.14  to 
0.42  per  cent.,  while  the  total  solids  varied  from  10.18  to  13.65 
per  cent.  The  lactose  (calculated)  percentage  was  from  5.6 
to  7.4.  An  average  colostrum  milk  contains  four  per  cent,  of 
fat,  1.9  per  cent,  of  proteids,  6.5  per  cent,  of  lactose,  and  0.2 
per  cent,  of  ash,  making  the  total  solids  12.5  per  cent,  and 
water  87.5  per  cent. 

Microscopical  examination  of  the  corpuscles  by  A.  E.  Taylor 
showed  a  small,  irregular,  but  much  degenerated  nucleus. 
The  protoplasm  is  more  or  less  filled  with  large  and  small 
granules,  only  a  few  of  which  are  stained  by  osmic  acid.  These 
granules  will  not  stain  with  acid,  basic,  and  neutral  dyes; 
they  show  the  characteristics  of  proteids  in  their  reactions. 
The  few  granules  which  are  stained  with  osmic  acid  are  probably 
fatty.  The  most  marked  feature  is  the  constant  and  excessive 
degeneration. 

Composition  of  Mother's  Milk. 

Before  discussing  the  elements  which  constitute  mother's  milk, 
it  will  be  well  to  quote  the  average  percentages  of  the  different 
ingredients  as  they  are  given  in  some  of  the  leading  text-books. 

In  glancing  over  the  tables,  it  at  once  appears  that  there 
are  greater  variations  in  the  proteid  content  than  in  that  of 
the  other  ingredients.  Monti's  maximum  of  five  per  cent,  pro- 
teids must  be  considered  an  abnormally  high  figure. 

Although  variations  in  the  fat  and  proteid  content  may 
occur  at  any  period  of  lactation,  it  will  be  shown  in  the  fol- 
lowing pages  that  the  composition  of  mother's  milk  tends  to 
approximate  a  certain  average  after  lactation  has  become  well 
established. 


MOTHER'S   MILK. 


23 


Baginskv.5 

Max. 

MONTI.! 

Min. 

19 

Aver. 

HOLT.« 

ROTCH.»» 

Per  cent. 

Per  cent. 

Per  cent. 

Per  cent. 

Per  cent. 

Per  cent. 

Water 

.      87-88.5 

90.1 

84.9 

88.6 

85.5-89.82 

87-88 

Solids 

11.5 
1.7 

16.5 
5.0 

10.0 
1.2 

11.0 
2.7 

12-13 

Proteids . . 

1-2.75 

1-2 

Casein .... 

1.2 

0.5 

3.8-4.07 

4.0 

2.0 

3.0 

Albumin  .  . 

Fat 

3-5 

3-4 

Lactose  . . , 

6-7.03 

7.0 

3.0 

5.0 

6-7 

6-7 

Ash 

0.2-0.21 

0.2 

0.1 

0.20 

0.18-0.25 

0.1-0.2 

Baginsky 's  table  seems  to  be  averaged  from  the  figures  of  Lehman  n  and 
Hoffmann. 

Monti's  table  is  drawn  from  the  figures  of  Pfeiffer,  Konig,  Hoffmann, 
and  Johannessen. 

Holt's  table  is  based  on  the  analyses  of  Pfeiffer,  Kdnig,  Leeds,  Harring- 
ton, and  others. 

Rotch's  table  represents  the  analyses  of  Konig,  Forster,  Meigs,  Harring- 
ton, and  others. 

Proteids. 

The  chief  proteids  in  mother's  milk  are  casein,  lactalbumin, 
and  lacto-globulin.  That  lactalbumin  is  present  in  mother's 
milk  is  maintained  by  Lehmann,  Schlossmann,  Bendix,  Ba- 
ginsky, Monti,  Holt,  Botch,  and  others,  whereas  Pfeiffer  and 
Duclaux  deny  its  existence. 

The  proteids  of  mother's  milk  are  partly  in  solution  and 
partly  in  suspension  (Botch).  The  casein  is  in  suspension  by 
virtue  of  the  presence  of  calcium  phosphate,  with  which  it  is 
probably  combined,  while  the  lactalbumin  is  in  solution  and 
resembles  serum-albumin  (Holt,  Monti).  Schlossmann  states 
that  casein  contains  phosphorus,  and  that  lactalbumin  contains 
sulphur  in  soluble  form.  In  his  latest  series  of  analyses  Schloss- 
mann estimates  the  average  amount  of  total  proteids  in  mother's 
milk  at  1.56  per  cent.  In  an  earlier  series  of  analyses  he  found 
that  of  the  total  proteids  sixty-three  per  cent,  were  represented 
by  casein  and  thirty-seven  per  cent,  by  lactalbumin.    According 


24  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

to  Lehmann  and  Bendix,  the  total  proteids  equal  1.7  per  cent., 
and  the  ratio  of  casein  to  albumin  is  as  1.2  to  0.5  per  cent. 
Camerer  asserts  that  older  milk  contains  relatively  more  casein 
than  albumin,  and  Monti  confirms  this  statement.  In  the 
latter's  opinion,  during  the  first  months  of  life  the  breast-milk 
is  characterized  by  a  high  content  in  lactalbumin  as  compared 
with  casein.  With  the  advance  of  lactation  the  amount  of 
lactalbumin  diminishes  very  decidedly,  so  that  in  the  last 
months  the  casein  predominates.  Schlossmann  considers  that 
this  large  proportion  of  soluble  albumin  is  of  great  help  to 
digestion,  since  the  infant  obtains  a  considerable  part  of  the 
nitrogen  he  requires  in  a  forgfl  in  which  it  can  be  directly 
absorbed,  whereas  casein  has  to  undergo  complicated  changes 
before  it  is  ready  for  absorption.  The  presence  of  lactalbumin 
causes  precipitation  of  the  casein  in  much  finer  flakes,  as  does 
also  that  of  the  finely  emulsified  fat.  On  the  other  hand, 
Baginsky  doubts  whether  a  marked  difference  exists  between 
casein  and  lactalbumin  in  regard  to  their  digestibility  and 
ease  of  absorption,  since  there  is  ground  for  the  assumption 
that  mother's  milk  is  absorbed  in  toto  by  the  lacteals, — that  is, 
without  special  preparation.  (It  seems  questionable  whether 
the  casein  of  mother's  milk  can  be  absorbed  as  such. — Editors.  ) 
Monti  says  that  during  the  first  two  months  of  lactation 
normal  milk  has  a  proteid  content  of  from  two  to  two  and  a 
half  per  cent.  (Percentages  above  two  after  the  first  three 
or  four  weeks  of  lactation  may  be  considered  above  the  aver- 
age.— Editors.)  If  the  ratio  of  casein  to  albumin  is  altered, 
especially  if  too  little  fat  (less  than  three  per  cent.)  is  present, 
such  a  milk  will  disagree.  A  proteid  content  below  two  per 
cent.,  or  even  down  to  one  per  cent.,  may  agree  with  the  child 
at  this  period,  but  the  latter  proportion  is  too  low  for  proper 
thriving.  Over  three  per  cent,  is  abnormal  and  will  disagree 
at  any  period  of  lactation.  After  the  second  month  from  one 
to  one  and  a  half  per  cent,  of  proteids  is  present,  and  such 
a  proportion  will  suffice  for  the  needs  of  the  infant  if  the 


MOTHER'S   MILK.  25 

fat  percentage  is  normal.  Below  one  per  cent,  of  proteids, 
however,  is  always  abnormal,  and,  even  if  the  fat  is  normal 
in  quantity,  children  will  not  thrive  on  such  a  milk. 

Analyses  of  Proteids  in  Human  Milk. 

In  1895  Johannessen  75  published  the  results  of  his  investi- 
gations of  mother's  milk,  based  on  one  hundred  and  fifty  sam- 
ples from  twenty-five  healthy  women;  they  were  between 
twenty  and  forty-six  years  of  age,  most  of  them  living  in  the 
city  and  in  needy  circumstances.  The  analyses  were  made 
daily  for  months  together  in  all  but  a  few  of  the  eases.  Fifty 
cubic  centimetres  were  drawn  from  each  breast  directly  be- 
fore and  directly  after  nursing.  Using  the  Kjeldahl  method 
and  the  Hammarsten-Sebelien  coefficient  (6.37),  he  found  that 
the  total  proteid  content  averaged  1.1  per  cent.  In  ten  ex- 
ceptions it  rose  to  2.6  and  2.8  per  cent.  For  the  first  six 
months  the  proteid  average  was  1.19  per  cent.,  for  the  next 
six  months  0.99  per  cent.,  and  after  the  first  year  0.90  per 
cent.  The  difference  between  the  nitrogen  present  in  the  form 
of  casein,  albumin,  and  globulin  and  the  total  nitrogen 
amounted  to  0.025  per  cent,  nitrogen.  This  must  be  consid- 
ered to  represent  extractives. 

Heubner  169  gives,  as  the  average  proteid  content  after  the 
first  week,  from  1.02  to  1.2  per  cent.,  based  on  the  analyses 
of  Johannessen,  Forster,  F.  R.  Hoffmann,  Camerer  and  Sold- 
ner,  Munk,  Finkelstein,  Hirschfeld,  and  others.  The  results 
of  Adriance's  analyses  4  gave  a  proteid  percentage  of  1.95  up 
to  the  third  week;  from  that  time  to  the  fifteenth  month  the 
proteid  average  was  1.11  per  cent. 

Meigs's  98  analyses  of  mother's  milk,  which  included  samples 
from  forty  women,  gave  a  proteid  percentage  of  1.05.  His 
samples  were  obtained  at  varying  intervals  after  nursing.  Only  a 
small  proportion  represented  the  milk  of  individual  cases,  the 
remainder  being  the  mixed  milk  of  a  large  number  of  women. 

Biedert  7  states  that  woman's  milk  has  a  proteid  content, 


26 


THE   ARTIFICIAL   FEEDING   OF   INFANTS. 


reckoned  as  nitrogen,  of  from  0.85  to  1.72  per  cent.;  reckoned 
as  proteid  plus  undetermined  remnant,  of  from  1.11  to  2.65 
per  cent. ;  whereas  the  proteids  of  cow's  milk,  reckoned  as  nitro- 
gen, may  be  put  at  from  2.8  to  3.3  per  cent.,  and,  reckoned  as 
total  proteid  constituents,  at  from  3.08  to  3.44  per  cent.  The 
composition  of  each  mother's  milk  has  individual  characteris- 
tics, especially  as  to  its  nitrogenous  and  fat  content;  hence  it  is 
absurd  to  regard  the  average  of  mother's  milk  as  a  model,  and 
unjust  not  to  set  great  weight  on  the  quantitative  relations. 

For  purposes  of  comparison  let  us  examine  Pfeiffer's  "  Ta- 
ble of  Human  Milk  Constituents  at  All  Periods  of  Lactation, 
including  Two  Analyses  of  Colostrum"  (one  hundred  analy- 
ses in  all).118 


Proteids 

estimated  as 

casein. 

Per  cent. 

First  month  (including  colostrum)       2.9 

Second  month 2.0 

Third  month 1.9 

Fourth  month 1.7 

Fifth  month 1.4 

Sixth  month 1.5 

Seventh  month 1.5 

Eighth  month 1.6 

Ninth  month 1.5 

Tenth  month 1.7 

Eleventh  month 1.4 

Twelfth  month .... .    1.7 

Thirteenth  month 1.6 


Sugar. 


Per  cent. 

Per  cent. 

Per  cent. 

2.7 

5.7 

0.23 

3.3 

6.3 

0.18 

2.7 

6.4 

0.18 

3.9 

6.6 

0.15 

3.6 

7.3 

0.19 

2.7 

6.8 

0.23 

3.2 

6.8 

0.17 

3.3 

6.3 

0.15 

2.4 

6.6 

0.16 

4.2 

6.2 

0.14 

3.5 

6.6 

0.14 

5.3 

6.0 

0.16 

2.9 

6.6 

0.15 

Pfeiffer's  analyses  show  that  mother's  milk  contains  in  the 
first  days  after  birth  a  high  percentage  of  proteids  and  salts 
and  a  low  fat  and  sugar  content.  During  the  progress  of 
lactation  the  proportions  of  proteids  and  salts  gradually  de- 
crease while  the  sugar  increases;  the  fats  vary  constantly. 


MOTHER'S   MILK.  27 

Schlossmann;  Adriance,  and  Richmond  confirm  the  latter 
statement.  Konig's  table "  of  the  average  composition  of 
mother's  milk,  based  on  two  hundred  analyses,  may  also  be 
cited,  although  it  cannot  be  considered,  in  the  light  of  more 
recent  investigations,  to  represent  the  correct  proportions  of 
casein  to  albumin.  The  percentage  of  salts  given  (0.31)  is 
abnormally  high. 

Per  cent. 

(  Casein 1.03    )    tt  t 

Proteids....  \   ...,       .  ,  _  >   2.29 


(  Casein 1.03    ) 

j  Albumin 1.26   j 


Fat 3.78 

Sugar 6.21 

Salts 0.31 

Water.... 87.41 

Solids 12.59 

Magnus  Blauberg.13  In  1894  the  results  of  Lehmann's  in- 
vestigations were  published  by  Hempel.167  This  author  found 
the  average  composition  of  woman's  milk  to  be:  casein  1.2 
per  cent.,  albumin  0.5  per  cent.,  fat  3.8  per  cent.,  milk-sugar 
six  per  cent.,  ash  0.2  per  cent.,  water  88.5  per  cent.  Lehmann 
found  casein  to  exist  as  a  double  salt  of  calcium  casein  with 
lime  phosphate.  Cow's  milk  casein  contained  6.6  per  cent, 
calcium  phosphate  and  0.723  per  cent,  sulphur,  while  mother's 
milk  casein  contained  1.09  per  cent,  sulphur  and  only  3.2 
per  cent,  calcium  phosphate;  hence  he  concludes  that  the  two 
caseins  are  not  identical. 

The  proteid  averages  of  Konig  and  Pfeiffer  were  considered 
the  standard  until  1894,  when  Heubner,  in  the  Congress  of 
Hygiene  at  Pesth,  announced  the  results  of  Professor  Hoff- 
mann's (Leipsic)  analyses.  Hoffmann  obtained  a  large  num- 
ber of  samples  from  the  same  women,  and  his  investigations 
covered  a  long  period.  He  concluded  that  after  the  third  week 
from  delivery,  milk  varies  little  in  its  composition  from  month 
to  month,  and  gives  the  following  average:  proteids  1.03,  fat 
4.07,  sugar  7.03,  and  ash  0.21  per  cent. 


28 


THE   ARTIFICIAL   FEEDING   OF   INFANTS. 


Soldner,40  at  Camerer's  instigation,  determined  to  subject 
previous  methods  of  analysis  to  a  rigid  test.  He  found  by 
a  series  of  parallel  experiments  that  the  Kjeldahl  method  for 
estimating  nitrogen  was  perfectly  applicable  to  milk,  and  gave 
reliable  results  (agreeing  in  this  with  Munk,  in  opposition 
to  Salkowsky,  who  states  that  the  Kjeldahl  method  gives  too 
low  figures  for  casein).  The  analyses  of  mother's  milk  by 
Soldner  were  based  on  samples  of  the  breast-milk  taken 
throughout  the  day;  the  breasts  were  evacuated  as  completely 
as  possible  and  the  infants  nursed  during  the  night. 


Proteid  values  (Kjeldahl  method). 


Time  after  birth.  N  X  6.25 

Per  cent. 

Colostrum,  early 5.8 

Colostrum,  late 3.17 

Fifth  and  sixth  days 2.04 

Eighth  and  ninth  days  ....  1.54 

Ninth  day 1.47 

Ninth  and  eleventh  days  . .  1.74 
Fourth,  fifth,  and  eleventh 

days 1.69 

Eleventh  day 1.74 

Twentieth  and  twenty-first 

days 1.36 

Twenty-ninth  and  thirtieth 

days 1.13 

Seventy-fourth  day 0.95 

One  hundred  and  thirteenth 

day 0.95 

Two  hundred  and  twenty- 
ninth  day 0.88 


According 
to  Munk. 

Per  cent. 
5.35 
2.90 
1.81 
1.42 
1.40 
1.61 


Proteid  plus 
unknown 

extractives. 
Per  cent. 

7.34 
4.26 
2.66 
2.42 
2.20 
2.03 


1.56  2.27 

1.61  2.55 

1 


1.11 


1.04 

0.88 


0.88 


0.81 


1.61 


1.39 
0.86 


0.82 


Unknown 
extrac- 
tives. 

Per  cent. 

1.99 
1.33 
0.85 
1.00 
0.80 
0.42 

0.71 
0.94 

0.50 

0.35 
0.02 

0.06 

0.01 


Camerer   and   Soldner   conclude   from   this  work  that  the 
commonly  accepted  values  for  proteids  are  too  high.     They 


MOTHER'S   MILK.  29 

emphasize  the  high  percentage  of  extractives  during  the  first 
three  weeks  of  life.  Such  substances  are  only  sparingly  found  in 
cow's  milk,  except  in  colostrum ;  among  them  are  traces  of  urea, 
hypoxanthin,  creatinin,  potassium  sulphocyanate,  and  lecithin. 

Camerer  and  Soldner  give  this  average  for  mother's  milk 
at  the  middle  of  the  second  week:  sugar  6.5  per  cent.,  fat 
3.28  per  cent.,  ash  0.27  per  cent.,  proteids  (according  to  Munk) 
1.52  per  cent.,  citric  acid  0.05  per  cent.,  unknown  extractives 
0.78  per  cent.;  total  solids  12.40  per  cent.  The  number  of 
samples  analyzed  is  not  sufficiently  large  to  establish  an  aver- 
age for  the  whole  period  of  lactation. 

Carter  and  Kichmond.39  The  table  drawn  up  by  these 
authors  represents  the  average  of  analyses  of  ninety-four  sam- 
ples of  human  milk,  taken  almost  entirely  from  women  in  the 
lying-in  department  of  the  Birmingham  Workhouse  Infirmary. 
With  seven  exceptions,  all  the  samples  were  obtained  at  some 
time  within  the  first  month  after  delivery.  In  the  majority 
of  the  cases  two  samples  were  taken,  one  before  and  one  after 
suckling;  the  quantity  drawn  off  is  not  stated.  Most  of  the 
mothers  were  healthy  and  most  of  the  children  thrived. 

For  the  purposes  of  analysis  the  Kitthausen  method,  slightly 
modified,  was  used.  The  results  of  the  work  may  be  consid- 
ered to  establish  an  average  for  the  first  three  weeks  after 
birth,  since  seventy-six  out  of  the  ninety-four  samples  derive 
from  this  period  of  lactation.  Only  four  separate  breast- 
milks  were  examined  during  the  fourth  week,  but  three  during 
the  second  month,  three  during  the  third  month,  and  one  at 
nine  and  a  half  months. 

Per  cent. 

Water 88.04 

Fat 3.07 

Sugar 6. 59 

Proteids 1.97 

Salts 0.26 

Specific  gravity 1031.3 


30  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

The  proteid  average  during  the  first  six  days  of  life  was 
2.25  per  cent.,  for  the  first  two  weeks  2.05  per  cent.,  and  during 
the  fourth  week  1.72  per  cent.;  after  that  time  it  showed  a 
gradual  diminution  throughout  lactation.  The  same  diminu- 
tion was  noticed  in  the  ash, — from  0.30  per  cent,  in  the  first 
week  to  0.26  per  cent,  in  the  second  week,  0.22  per  cent,  in 
the  third  and  fourth  weeks,  and  0.21  per  cent,  after  one  month. 
The  sugar  percentage  showed  a  tendency  to  increase  with  the 
progress  of  lactation. 

The  greatest  variations  were  observed  in  the  fat  content, 
the  next  highest  in  the  proteid  percentage,  and  the  least  in 
the  sugar. 

Leeds,166  on  the  basis  of  eighty  analyses  of  human  milk, 
using  the  Gerber-Kitthausen  method,  asserts  that  the  proteid 
average  in  breast-milk  is  about  two  per  cent.  He  considers 
that  the  proteids  are  the  most  variable  constituent  in  human 
milk,  the  fat  the  next  most  variable,  and  the  sugar  the  least 
variable.  Each  sample  was  taken  from  both  breasts  (the 
quantity  obtained  not  stated),  and  twenty-six  out  of  sixty-eight 
samples  were  taken  from  two  to  three  hours  after  nursing, 
the  remainder  at  intervals  varying  from  five  minutes  to  five 
hours  after  the  child  had  nursed.  Of  the  total  number  of 
analyses,  forty-one  cover  the  first  month  of  lactation,  six 
samples  were  examined  during  the  second  and  third  months 
respectively,  three  during  the  fourth  and  fifth  months,  and 
four  during  the  sixth  month  and  period  following.  This 
number  of  analyses  is  hardly  large  enough  to  establish  an 
average  for  any  period  of  lactation  except  the  first  month; 
we  may,  however,  accept  Leeds's  proteid  average  of  two  per 
cent,  as  a  reliable  estimate  for  the  first  four  weeks  of  life. 
Leeds  found  that  the  proteid  content  of  human  milk  was 
highest  at  the  beginning  (over  two  per  cent.)  and  became 
less  with  the  progress  of  lactation;  the  sugar  percentage  was 
lowest  in  the  colostrum  period,  but  soon  rose  and  remained 
pretty  constant.     The  fat  content  is  high  in  the  colostrum 


MOTHER'S   MILK.  31 

period,  but  falls  after  the  tenth  day;  the  salts  are  slightly  in 
excess  during  the  first  ten  days,  but  vary  little  during  the 
remainder  of  lactation. 

In  January,  1897,  John  and  Vanderpoel  Adriance  4  pub- 
lished the  results  of  their  analyses  of  the  breast-milk  of  one 
hundred  and  twenty  cases.  All  the  mothers  were  healthy  and 
of  an  average  age  of  twenty-five  years;  sixty-five  were  primi- 
parse  and  fifty-five  multipara.  The  breasts  were  not  entirely 
evacuated  for  each  analysis,  but  the  sample  was  taken  after 
the  child  had  nursed  for  two  minutes.  The  results  of  these 
analyses  show  wide  variations  in  the  fat  content  at  different 
periods  of  lactation,  a  gradual  and  steady  increase  in  the  sugar 
percentage,  and  a  gradual  decrease  in  the  percentages  of  pro- 
teids  and  salts.     The  Kjeldahl  method  was  used. 

Adriance  computed  that  the  average  specific  gravity  during 
lactation  was  1030,  the  average  fat  percentage  3.83,  the  aver- 
age total  solids  12.20,  and  the  average  amount  of  water  present 
87.80  (up  to  the  eighth  month).  He  found  variations  at  dif- 
ferent periods  of  lactation,  shown  in  the  accompanying  table. 

Carbohydrates.  Proteids.  Ash. 

Per  cent.  Per  cent.  Per  cent. 

Second  to  fourteenth  day 5.80-6.63  2.77-1.70  0.27-0.20 

Onemonth 6.68  1.58  0.19 

Three  months 6.72  1.44  0.18 

Six  months 6.78  1.25  0.16 

Nine  months 6.84  1.04  0.16 

Twelvemonths 6.90  0.83  0.15 

Fifteen  months 6.96  0.63  0.14 

Schlossmann,241  in  the  Archiv  fur  Kinderheilkunde,  Bd. 
xxx.,  1900,  emphasizes  the  importance  of  allowing  a  sufficient 
interval  of  time  to  elapse  after  the  last  nursing  before  obtain- 
ing the  sample  to  be  investigated;  also  the  necessity  of  get- 
ting, for  accurate  results,  as  nearly  as  possible  the  same  quan- 
tity of  milk  which  the  infant  would  have  taken  from  the  breast. 


32 


THE   ARTIFICIAL   FEEDING   OF   INFANTS. 


The  following  table  represents  the  results  of  two  hundred  and 
eighteen  analyses  of  mother's  milk  at  different  periods  of  lacta- 
tion. The  Kjeldahl  method  was  used.  The  proportion  of  solu- 
ble albumin  to  casein  was  not  considered. 


No.  of 

cases 

analyzed. 

No.  of  days 
after  birth. 

Fat  per 
cent. 

Nitrogen 
per  cent. 

N  X  6.25 
per  cent. 
=  proteids. 

Sugar 
per 
cent. 

Calories 
per  litre. 

6 

9-10 

4.23 

0.29 

1.81 

6.92 

744 

25 

11-20 

4.63 

0.29 

1.81 

6.89 

780 

41 

21-30 

4.53 

0.31 

1.94 

6.77 

772 

21 

31-40 

5.00 

0.24 

1.50 

6.97 

805 

13 

41-50 

5.41 

0.28 

1.75 

6.80 

847 

24 

51-60 

4.62 

0.25 

1.56 

7.28 

785 

10 

61-70 

4.69 

0.23 

1.44 

6.94 

773 

19 

71-100 

5.39 

0.20 

1.25 

6.77 

823 

25 

101-140 

5.10 

0.20 

1.25 

6.94 

803 

15 

141-200 

4.02  (4.74) 

0.217 

1.29 

6.89 

702(769) 

19 

over  200 

5.55 

0.21 

1.31 

7.33 

863 

218 

The  average  values  in  mother's  milk  during  the  first  seven 
months  of  lactation  are  as  follows:  proteids  1.56  per  cent., 
fat  4.83  per  cent.,  sugar  6.95  per  cent.,  nitrogen  0.25  per  cent., 
calories  per  litre,  782. 

The  results  of  these  analyses  show  that: 

I.  The  proteid  percentage  in  mother's  milk  is  very  high 
in  the  first  weeks  after  birth,  diminishing  after  the  thirtieth 
day.  From  the  sixtieth  day  we  observe  a  more  decided  and 
rapid  fall  in  the  proteid  content.  It  is  remarkable  how  uni- 
form the  composition  of  the  milk  remains  after  the  seventieth 
day. 

II.  The  variations  in  the  fat  content  are  much  less  regular. 
We  see  the  fact  again  demonstrated  that  in  mother's  milk 
the  infant  obtains  a  food  decidedly  richer  in  fat  than  is  present 
in  any  kind  of  artificial  food.     The  fat  of  mother's  milk  is 


MOTHER'S  MILK.  33 

usually  well  digested  by  the  infant,  even  when  it  is  excessive  in 
amount. 

III.  There  is  no  regularity  in  the  variations  in  the  sugar 
content.  We  find  in  the  high  fat  and  sugar  percentage  the 
characteristic  prevalence  in  mother's  milk  of  the  non-nitroge- 
nous over  the  nitrogenous  substances. 

IV.  In  such  cases  as  were  observed  over  a  long  period  of 
time  the  composition  of  the  milk  approximated  very  closely 
to  the  average  figures  given.  A  low  proteid  percentage  was 
constantly  observed  in  the  later  months.  Schlossmann  found 
that  the  amount  of  milk  secreted  by  a  strong,  healthy  mother 
was  rather  in  excess  of  that  generally  accepted.  In  a  series  of 
daily  estimations,  carried  out  for  long  periods  of  time,  the 
quantity  secreted  varied  from  one  thousand  cubic  centimetres 
to  sixteen  hundred  cubic  centimetres  daily.  Schlossmann 
thinks  that  it  is  more  common  for  the  nursing  child  to  get 
too  much  than  too  little,  since  many  women  have  a  super- 
abundance of  milk.  In  cases  in  which  the  flow  is  very  easy 
and  rapid,  the  child  may  take  in  a  few  moments  enough  to 
fill  the  stomach. 

Rotch.119  "  Reasoning  from  the  strong  analogy  which  must 
exist  between  human  milk  and  cow's  milk,  and  being  aware 
of  the  great  variations  which  occur  in  the  latter,  we  may 
assume  that  human  milk  is  liable  to  vary  considerably  in  its 
composition  with  different  milkings."  Our  present  knowledge 
of  human  milk  is  not  sufficiently  exact  for  the  formula- 
tion of  a  table  to  show  the  composition  of  woman's  milk  at 
different  periods  of  her  lactation.  "  We  must  also  understand 
that  human  milk  of  normal  quality  and  proving  to  be  equally 
nutritious  to  the  special  infants  fed  on  it  may  vary  considerably 
in  the  percentages  of  all  its  elements  and  in  the  combinations 
of  these  percentages.  This  fact  is  well  illustrated  in  the  fol- 
lowing table,  showing  the  analyses  of  fourteen  specimens  of 
human  milk,  all  differing  in  the  combinations  of  their  different 
elements. 

3 


34  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

Human  Breast-Milk  Analyses. 
(Mothers  healthy  and  infants  all  digesting  well  and  gaining  in  weight. ) 


I. 

Per  cent. 

II. 

Per  cent. 

in. 

Per  cent. 

IV. 

Per  cent. 

v. 

Per  cent. 

VI. 

Per  cent, 

VII. 

Per  cent. 

Fat 

.     5.16 

4.88 

4.84 

4.37 

4.11 

3.82 

3.80 

Lactose  . . . 

.     5.68 

6.20 

6.10 

6.30 

5.90 

5.70 

6.15 

Proteids 

.     4.14 

3.71 

4.17 

3.27 

3.71 

1.08 

3.53 

Ash 

.     0.17 

0.19 

0.19 

0.16 

0.21 

0.20 

0.20 

Total  solids 

.   15.15 

14.98 

15.30 

14.10 

13.93 

10.80 

13.68 

Water .... 

.  84.85 

85.02 

84.70 

85.90 

86.07 

89.20 

86.32 

100.00 

100.00 

100.00 

100.00 

100.00 

100.00 

100.00 

VIII. 

Per  cent. 

IX. 

Per  cent. 

X. 

Per  cent. 

XI. 

Per  cent. 

XII. 
Per  cent. 

XIII. 

Per  cent. 

XIV. 

Per  cent. 

Fat 

.     3.76 

3.30 

3.16 

2.96 

2.36 

2.09 

2.02 

Lactose 

,     6.95 

7.30 

7.20 

5.78 

7.10 

6.70 

6.55 

Proteids 

,     2.04 

3.07 

1.65 

1.91 

2.20 

1.38 

2.12 

Ash 

,     0.14 

0.12 

0.21 

0.12 

0.16 

0.15 

0.15 

Total  solids . 

12.89 

13.79 

12.22 

10.77 

11.82 

10.32 

10.84 

"Water 

87.11 

86.21 

87.78 

89.23 

88.18 

89.68 

89.16 

100.00 

100.00 

100.00 

100.00 

100.00 

100.00 

100.00 

"  In  a  number  of  these  cases,  when  one  of  the  infants  who 
was  doing  well  on  its  own  mother's  milk  was  fed  with  one  of 
the  other  combinations,  it  soon  became  sick,  and  had  to  be 
changed  back  to  the  one  adapted  to  its  digestion.  Human 
milk  may,  then,  be  considered  to  represent  not  an  especial  food 
but  a  combination  of  foods,  and  its  fat,  sugar,  proteids,  and 
ash  to  represent  these  different  foods.  In  other  words,  we  find 
by  experience  that  the  digestive  capabilities  of  infants  differ 
just  as  do  those  of  adults,  and  that  nature  provides  a  number 
of  varieties  of  good  human  milk  adapted  to  the  varying  idiosyn- 
crasies of  infants." 


MOTHER'S   MILK.  35 

Variations  in  the  proteid  content  of  mother's  milk  may 
occur  exceptionally,  as  follows: 

From  0.6  -2.8    per  cent ( Johannessen 75). 

From  0. 7  -4. 5    per  cent ( Holt 69 ) . 

From  0.85-4.86  per  cent (Leeds166). 

From  0.57-4.25  per  cent (Kdnig"119). 

From  1.10-3.62  per  cent (Twenty-nine  analyses  of  the  Col- 
lege of  Physicians  and  Surgeons, 
New  York,  cited  by  Kotch119). 

FAT. 

Monti."  Fat  as  found  in  mother's  milk  consists  of  spherical 
bodies  which  refract  powerfully.  They  are  surrounded,  by 
molecular  attraction,  by  a  layer  of  casein  which  prevents  their 
agglutination.  The  earlier  view  that  they  were  surrounded 
by  an  albuminous  envelope  has  been  controverted  by  more 
recent  investigators,  especially  Quincke.  According  to  Woll, 
each  cubic  centimetre  of  milk  contains  from  1,030,000  to 
5,750,000  fat-droplets.  Their  size  varies  from  0.001  to  0.004 
millimetres  (Fleischmann),  and  from  0.0024  to  0.0046  milli- 
metres (Woll). 

In  general  we  can  distinguish  three  forms  of  fat-globules: 
(1)  The  very  large.  (2)  The  medium-sized,  which  generally 
constitute  the  chief  part  of  a  good  milk.  (3)  Punctiform 
or  finely  granular. 

On  the  basis  of  numerous  personal  investigations  which  cor- 
respond with  the  generally  accepted  figures,  Monti  finds  that 
the  normal  fat  content  of  mother's  milk  varies  from  two  and 
a  half  to  four  per  cent.  Giarre  and  Biagini,  from  one  hundred 
and  forty-nine  cases,  obtained  similar  results.  Below  two  per 
cent,  and  above  five  per  cent,  are  abnormal.  In  the  milk  of 
anaemic  and  weakly  women  we  often  find  a  fat  content  of  from 
one  to  one  and  a  half  per  cent.,  and  in  such  cases  finely  granular 
(Class  III.)  fat-droplets  predominate. 


36  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

The  fats  consist  of  butyric,  caproic,  caprylic,  myristic,  pal- 
mitic, stearic,  and  oleic  acids.  According  to  Ruppel,  mother's 
milk  is  comparatively  poor  in  volatile  acids :  of  the  non-vola- 
tile, oleic  acid  forms  one-half ;  palmitic  and  myristic  are  in 
excess  over  stearic  acid.* 

Milk  containing  very  large  fat-droplets  (Class  I.)  is  apt 
to  be  very  rich  in  fat  (Fleischmann).  These  may  be  found  in 
excess  in  the  secretion  of  older  women  and  of  those  who  have 
nursed  for  a  long  period,  also  during  menstruation  and  febrile 
disturbances.  In  watery  milk,  poor  in  fat,  there  may  be  a 
predominance  of  small  corpuscles  (Class  III.). 

The  percentage  of  fat  in  mother's  milk  is  subject  to  wide 
and  constant  variations  throughout  lactation.  The  average 
content  is  variously  stated: 

Per  cent. 

Mendez  de  Leon (after  the  third  week)  4.14 

Hoffmann (after  the  second  week)  4.00 

Richmond (for  the  whole  period  of  lactation)  3.07 

Pfeiffer (for  the  whole  period  of  lactation)  3.11 

Johannessen  .  . .  .(for  the  whole  period  of  lactation)  3.21 

Lehmann (for  the  whole  period  of  lactation)  3.80 

Adriance (for  the  whole  period  of  lactation)  3.83 

Leeds (for  the  whole  period  of  lactation)  4.13 

Schlossmann. . .  .(for  the  whole  period  of  lactation)  4.83 

Variations  in  the  fat  content  of  mother's  milk  have  been 
given  as  follows: 

°  Per  cent. 

Adriance 1.31-7.61 

Johannessen 0.63-6.65 

Holt 1.12-6.89 

Chemical  Laboratory  of  College  of  Physicians 

and  Surgeons,  New  York 1.12-5.02 

Kdnig 1.71-7.60 

Leeds 2. 11-6. 89 

*  For  original,  see  E.  Laves,  Zeitschrift  fiir  Physiolog.  Chem.,  Bd. 
xix.,  and  W.  G.  Ruppel,  Zeitschrift  fiir  Biologie,  Bd.  xxxi. 


MOTHER'S  MILK.  37 

Kichmond  found  that  the  composition  of  the  fat  in  the  early 
part  of  lactation  was  different  from  that  towards  the  close 
of  this  period.  This  was  seen  by  studying  the  volatile  fatty 
acids.  Where  the  secretion  of  milk  is  deficient,  the  fat  may 
vary  from  one  per  cent,  before  nursing  to  four  per  cent,  after 
nursing. 

Sugar. 

The  percentage  of  sugar  may  fairly  be  stated  to  average 
from  six  to  seven.  Adriance  emphasizes  the  steady  slight  in- 
crease in  the  sugar  percentage  during  lactation,  from  5.80  on 
the  second  day  to  6.96  at  the  fifteenth  month.  Johannessen's 
average  of  4.67  per  cent,  throughout  lactation  seems  to  be 
decidedly  subnormal,  while  Meigs's  figure  of  7.40  per  cent, 
exceeds  the  average. 

Per  cent. 

Pfeiffer 6.3 

Leeds 6.93 

Johannessen 4.67 

Richmond 6.59 

Lehmann   6.0 

Meigs 7.4 

Schlossmann 6. 95 

Adriance 6.56 

Salts. 

The  majority  of  authors  state  that  the  average  percentage 
of  salts  in  mother's  milk  is  0.20.  The  proportion  diminishes 
during  lactation,  according  to  Adriance,  from  0.27  on  the 
second  day  to  0.14  at  the  fifteenth  month. 

Abnormal  variations  may  occur:  from  0.13  to  0.37  per  cent. 
(Leeds).  Pfeiffer  found  a  minimum  of  0.09  per  cent.;  Kich- 
mond a  maximum  of  0.50  per  cent.  Among  the  most  reliable 
analyses  of  the  salts  in  human  milk  are  those  made  for  Rotch 
in  1893  by  Harrington  and  Kinnicutt.  Six  quarts  of  milk 
were  analyzed  with  these  results : 


38  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

Per  cent. 

Calcium  phosphate 23.87 

Calcium  silicate 1.27 

Calcium  sulphate 2.25 

Calcium  carbonate 2.85 

Magnesium  carbonate ...    3.77 

Potassium  carbonate 23.47 

Potassium  sulphate 8.33 

Potassium  chloride 12.05 

Sodium  chloride 21.77 

Iron  oxide  and  alumina 0.37 

100.00 

This  represents  the  form  in  which  salts  probably  exist  in  milk. 

A  portion  of  the  lime  is  united  to  the  casein;  the  rest  is 
combined  with  phosphoric  acid  as  a  mixture  of  di-  and  tri- 
calcium  phosphates,  which  are  kept  soluble  and  held  in  sus- 
pension by  the  casein. 

The  phosphorus  in  woman's  milk  consists  mainly  of  casein- 
phosphorus,  nucleon,  and  lecithin;  it  is  nearly  all  held  in 
organic  combination,  whereas  in  cow's  milk .  less  than  half 
of  the  phosphorus  is  in  organic  combination.  Nucleon  is  the 
richest  in  phosphorus  of  the  organic  compounds  in  milk ;  Witt- 
maack's  186  investigations  showed  that  one  litre  of  cow's  milk 
contained  from  0.55  to  0.6  gramme,  and  one  litre  of  woman's 
milk  from  1.1  to  1.3  grammes  of  nucleon.  Nucleon  can  unite 
with  lime  and  fix  it  in  chemical  combination.  The  total  phos- 
phorus content  of  cow's  milk  is  1.5  grammes,  over  three  times 
that  of  mother's  milk,  0.47  gramme  (Siegfried188). 

Stoklasa  187  found  that  one  litre  of  cow's  milk  contained 
from  0.9  to  1.13  grammes  of  lecithin,  whereas  in  one  litre  of 
human  milk  there  were  present  from  1.7  to  1.86  grammes  of 
lecithin.  The  same  investigator  found  that  one  litre  of 
woman's  milk  contained  0.44  gramme  of  phosphoric  acid,  and 
one  litre  of  cow's  milk  contained  1.81  grammes  of  the  same. 


MOTHER'S   MILK.  39 

Of  the  phosphoric  acid  in  milk,  then,  0.153  is  represented  by 
lecithin  in  woman's  milk  and  0.091  in  cow's  milk;  of  the  total 
phosphorus  content  in  woman's  milk,  thirty-five  per  cent,  exists 
as  lecithin,  whereas  in  cow's  milk  lecithin  represents  but  five 
per  cent.  Lecithin  contains  from  3.84  to  4.12  per  cent,  of 
phosphorus ;  it  is  broken  up  by  the  process  of  sterilization  into 
cholin,  glycerin-phosphoric  acid,  and  fatty  acids. 

Variations  in  Composition. 

Koeppe  168  emphasizes  the  fact  that  constant  alterations  in 
the  composition  of  mother's  milk  occur  from  hour  to  hour 
and  day  to  day.  He  suggests  that  the  poor  results  often  ob- 
tained from  the  use  of  carefully  selected  pure  and  sterilized 
milk  are  due  to  its  uniform  consistence,  whereas  nature's 
product  shows  constant  variations. 

Adriance's  analyses  show  that  the  milk  of  primiparae  during 
the  third  month  of  lactation  is  richer  in  fats,  proteids,  salts, 
and  total  solids  than  average  milk;  the  sugar  percentage  is 
less  in  the  milk  of  primiparge.  In  the  milk  of  multipara? 
at  this  time  there  is  more  sugar  and  less  proteids  and  fat. 

Leeds  166  considers  that  lean  women  in  good  physical  con- 
dition furnish  a  milk  richer  in  albuminoids  than  those  of 
over-robust  habit. 

The  composition  of  milk  before  and  after  suckling  varies, 
especially  in  its  fat  percentage.  This  is  well  shown  by  Carter 
and  Richmond  39  in  a  table  deduced  from  the  observation  of 
thirtv-seven  cases: 


Water. . . 
Fat 

Sugar  . . . 
Proteids  . 
Ash .... . 


>re  suckling. 
Per  cent. 

After  suckling. 
Per  cent. 

88.33 

88.04 

2.89 

3.18 

6.51 

6.53 

1.99 

1.99 

0.28 

0.26 

Before  suckling. 
Per  cent. 

After  suckling. 
Per  cent. 

2.77 

3.94 

5.70 

5.09 

0.98 

0.95 

40  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

Johannessen  gives  the  following  differences : 


Water . . , 

Fat 

Sugar  . . , 
Proteids  , 
Ash 


Johannessen's  maximum  variation  in  the  fat  percentage  was 
from  1.51  before  to  4.01  after  suckling.  Forster  found  more 
marked  differences: 


Water. . , 

Fat 

Sugar  .  . . 
Proteids  . 
Ash 


Summary. 
If  we  draw  up  a  table  representing  the  results  of  the  most 
reliable  series  of  analyses  of  mother's  milk,  we  find  that  the 
variations  are  not  very  great,  and  that  the  figures  all  approxi- 
mate to  a  general  average.  The  high  estimates  for  the  proteids 
obtained  by  Pfeiffer,  Leeds,  and  Eichmond  may  be  partly 
accounted  for  by  the  fact  that  the  Ritthausen  method,  which 
they  employed,  gives  uniformly  high  results;  besides  this, 
the  majority  of  Leeds's  and  Richmond's  analyses  were  of 
samples  taken  during  the  first  three  or  four  weeks  of  lacta- 
tion (including  the  colostrum  period),  when  all  observers  are 
agreed  that  the  percentage  of  proteids  is  uniformly  high. 
Pfeiffer,  Leeds,  and  Richmond  found  that  the  proteid  per- 


Fore-milk. 

Middle  milk. 

Stripping 

Per  cent. 

Per  cent. 

Per  cent 

90.24 

89.68 

87.50 

1.70 

2.77 

4.51 

5.56 

5.70 

5.10 

1.13 

0.94 

0.71 

0.46 

0.32 

0.28 

MOTHER'S   MILK. 


41 


centage  diminished  after  the  first  month  of  lactation.  On 
the  other  hand,  the  low  estimates  of  the  total  proteids  reached 
by  Meigs  and  Johannessen  are  probably  explained  by  the  fact 
that  most  of  their  samples  came  from  needy  women  in  poor 
hygienic  surroundings.  The  tables  of  Pfeiffer,  Schlossmann, 
and  Adriance  are  in  accord  in  showing  that  the  total  proteids 
are  high  at  first  but  soon  fall,  to  maintain  a  fairly  constant 
average  during  the  height  of  lactation.  According  to  Schloss- 
mann, Adriance,  and  Soldner,  the  total  proteids  show  a  ten- 
dency to  gradually  diminish  until  (towards  the  end  of  the  first 
year)  they  rarely  exceed  one  per  cent. 


Number  of  cases. .      160 

Per 
cent. 

Fat 3.11 

Sugar 6.3 

Proteids 1.94 

Salts 0.19 

Water 88.22 

Solids 11.76 


hS 

* 

m 

H) 

m 

£ 

< 

80 

25 

90 

40 

43 

218 

120 

Pel- 
cent. 

Per 

cent. 

Per 
cent. 

Per 

cent. 

Per 
cent. 

Per 
cent. 

Per 
cent. 

4.13 

3.21 

3.07 

3.8 

4.28 

4.83 

3.83 

6.93 

4.67 

6.59 

6.0 

7.4 

6.95 

6.56 

1.99 

1.10 

1.97 

1.7 

1.05 

1.56 

1.30 

0.20 

0.26 

0.20 

0.10 

0.20 

86.73 

88.04 

88.5 

87.16 

87.80 

13.26 

11.89 

11.70 

12.83 

12.20 

On  the  basis  of  the  first  five  tables  quoted  above,  which  he 
says  represent  the  results  of  the  most  reliable  analyses  of 
human  milk,  Richmond  estimates  the  following  to  be  the  prob- 
able mean  composition  of  normal  human  milk  after  lactation 
has  become  regular: 

Per  cent. 

Water 88.2 

Fat 3.3 

Sugar 6.8 

Proteids    1.5 

Ash 0.2 


42  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

The  tables  of  Schlossmann  and  Adriance  deserve  special 
notice,  since  they  represent  the  result  of  analyses  covering  the 
whole  period  of  lactation  and  carried  out  by  uniform  methods. 

Richmond's  average  must  not  be  considered  to  represent  any- 
thing more  than  a  general  mean.  At  all  times  of  lactation 
analysis  of  the  breast-milk  will  show  greater  or  less  variations, 
in  the  proteid  and  fat  content  especially.  All  that  can  safely 
be  said  is  that  one  and  a  half  per  cent,  of  proteids  constitutes 
a  proportion  which  is  very  constantly  found  during  the  height 
of  lactation.  Variations  above  and  below  this  figure  are  fre- 
quent, so  that  we  may  regard  two  per  cent,  as  a  high  and 
one  per  cent,  as  a  low  proteid  content  in  mother's  milk.  Over 
two  and  under  one  per  cent,  may  be  considered  abnormal  ex- 
cept at  the  beginning  and  end  of  lactation. 

The  presence  of  0.5  per  cent,  of  soluble  proteids  in  mother's 
milk,  in  the  form  of  lactalbumin  and  lacto-globulin,  is  now 
generally  accepted.  These  substances  represent  from  one-third 
to  one-fourth  of  the  total  proteid  content,  they  are  readily 
digestible,  and  apparently  are  present  in  larger  proportion 
during  the  first  months  of  life,  when  the  child's  powers  of 
assimilation  are  little  developed. 

The  percentage  of  fat  in  mother's  milk  varies  normally  be- 
tween three  and  four  and  a  half.  Below  two  and  over  five 
are  abnormal.  Fat  is  the  most  variable  constituent  in  mother's 
milk ;  the  proportion  is  not  affected  by  the  period  of  lactation. 
The  fat  of  mother's  milk  differs  from  that  of  cow's  milk  in 
containing  fewer  volatile  acids;  it  is  also  in  a  much  finer 
state  of  emulsion,  and  is  therefore  easier  of  digestion. 

The  percentage  of  sugar  is  a  very  constant  one,  varying 
from  six  to  seven.  It  is  lowest  during  the  colostrum  period; 
from  that  time  on  it  steadily  increases  throughout  lactation. 
The  average  percentage  of  sugar  at  the  height  of  lactation  may 
be  estimated  as  six  and  one-half.    It  is  readily  assimilated. 

The  percentage  of  salts  averages  0.2.  It  is  highest  at  first 
and  diminishes  steadily  during  lactation.    In  contrast  to  cow's 


MOTHER'S   MILK.  43 

milk,  nearly  all  of  the  phosphorus  exists  in  organic  combina- 
tion.* 

The  ratio  of  the  nitrogenous  to  the  non-nitrogenous  elements 
in  woman's  milk  is  about  1  to  7.6;  in  cow's  milk  it  is  1 
to  2.3. 

*  Schlossmann  has  recently  asserted  that  the  previous  methods  of 
analysis  to  determine  the  phosphorus  content  of  milk  are  open  to  grave 
objections,  so  that  he  is  no  longer  prepared  to  state  that  an  essential 
difference  exists  between  mother's  milk  and  cow's  milk  as  regards 
the  amount  of  organic  phosphorus  present.  (See  Edlef sen's  article, 
Chapter  III.) 


CHAPTEE    III. 

COW'S  MILK. 

Practically,  the  secretion  of  the  domesticated  milch-cow 
has  come  into  universal  use  for  the  artificial  feeding  of  in- 
fants. As  substitutes  for  cow's  milk,  mare's  milk,  goat's  milk, 
and  ass's  milk  have  been  recommended,  especially  the  latter. 
H.  von  Ranke 124  states  that  ass's  milk  contains,  according 
to  the  latest  authorities,  casein  and  albumin  in  the  ratio  of 
one  hundred  to  eighty-one  (Soxhlet  and  Scheibe)  ;  [casein  1.32 
and  albumin  0.34  (Richmond)]  ;  fat  about  one  per  cent.,  sugar 
six  per  cent.,  and  ash  from  0.4  to  0.5  per  cent.  Notwithstand- 
ing its  low  fat  content,  it  is  well  adapted  for  use  in  the  first 
eight  to  twelve  weeks  of  life,  and  experience  has  proved  its 
value.  The  results  obtained  have  been  encouraging,  especially 
in  Paris,  where  it  is  largely  used  by  the  better  classes  (its 
price  is  one  dollar  a  quart).  The  cost  and  difficulty  of  ob- 
taining ass's  milk  have  prevented  its  coming  into  general  use; 
the  same  may  be  said  of  goat's  and  mare's  milk. 

Reaction. 
Cow's  milk  has  usually,  when  fresh,  an  amphoteric  reaction. 
At  times  it  may  be  feebly  alkaline.     With  phenol-phthalein 
the  reaction  is  always  acid  (Klimmer). 

At  ordinary  temperatures  milk  soon  becomes  acid  on  stand- 
ing. 

Specific  Gravity. 

Allowing  for  differences  of  temperature  of  the  milk  when 
tested,  Richmond  finds  that  the  specific  gravity  of  the  mixed 
milk  of  the  herd  rarely  falls  outside  of  the  limits  of  from 
44 


COW'S   MILK.  45 

1030  to  1034,  with  an  average  of  1032.  This  average  corre- 
sponds very  closely  with  those  obtained  by  other  investigators, 
with  the  exception  of  Leeds,  whose  figures  are  decidedly  higher 
(1039.7),  and  Klimmer,  who  finds  variations  at  a  temperature 
of  15°  C.  of  from  1027  to  1040. 

Eichmond.121  The  specific  gravity  is  dependent  on  two 
factors:  the  amount  of  solids  not  fat,  which,  being  dissolved 
in  water,  raise  the  specific  gravity;  and  the  fat,  which,  being 
lighter  than  water,  lowers  it. 

"  By  removing  the  fat  as  cream  (with  a  small  proportion 
of  the  other  constituents),  the  specific  gravity  of  the  milk  is 
raised.  By  the  addition  of  water,  the  specific  gravity  is  low- 
ered. The  specific  gravity  has  been,  and  is,  largely  used  as  a 
test  to  show  the  addition  of  water  to  milk;  for  the  detection 
of  large  amounts  of  water  in  milk  it  has  some  value. 

"  As  a  preliminary  test,  estimating  the  specific  gravity  is 
of  the  greatest  importance  and  should  never  be  neglected;  as 
an  absolute  test,  it  is  liable  to  be  greatly  misleading.  This 
is  shown  by  the  following  facts. 

*  I.  With  milk  of  1034  specific  gravity  at  least  ten  per 
cent,  of  water  could  be  added  before  it  would  be  suspected  by 
this  test. 

"  II.  If  the  cream  were  all  removed  from  a  milk  of  1032 
specific  gravity  we  would  have  a  product  of  about  1036  specific 
gravity,  and  an  addition  of  rather  more  than  ten  per  cent, 
of  water  would  bring  the  specific  gravity  back  to  1032. 

"  III.  If  to  milk  of  1032  specific  gravity  sufficient  cream 
be  added  to  raise  the  percentage  of  fat  four  per  cent.,  the 
specific  gravity  will  be  found  to  be  about  1028." 

Mixed  Milk. 
Practically,  all  authorities  are  agreed  in  recommending  the 
use  of  the  mixed  milk  from  a  herd,  in  order  to  dilute  the  harm- 
ful products  which  may  be  present  in  the  milk  of  a  single 
cow. 


46  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

Description. 
By  far  the  most  satisfactory  account  of  the  composition  and 
characteristics  of  cow's  milk  is  to  be  found  in  H.  Droop 
Eiohmond's  "  Dairy  Chemistry."  121  According  to  this  author, 
milk  is  essentially  an  aqueous  solution  of  lactose,  albumin, 
and  certain  salts,  holding  in  suspension  globules  of  fat,  and 
containing  casein  in  a  state  of  semi-solution,  together  with 
mineral  matters.  The  composition  of  cow's  milk  is  given  as 
follows,  on  the  basis  of  two  hundred  thousand  analyses  (Eng- 
lish) : 

Per  cent. 

Water 87.10 

Fal 3.90 

Lactose 4. 75 

Casein 3.00 

Albumin 0.40 

Ash 0.75 

Paul  Vieth  (for  twelve  years  analyst  to  the  Aylesbury  Dairy 
Company)  gives  the  average  ratio  between  lactose,  proteids, 
and  ash  in  milk  as  13  to  9  to  2.  Eichmond  found  this  marvel- 
lously exact. 

Variations  in  composition  may  occur  in  abnormal  milk : 

Per  cent. 

Fat from  2.79-10.5 

Lactose from  1.91-  4.66 

Proteids from  3.35-  4.58 

Ash from  0.76-  0.94 

In  England,  where  cows  are  milked  twice  a  day,  the  evening 
milk  is  almost  invariably  richer  in  fat  than  the  morning  milk. 
When  the  interval  between  milkings  is  twelve  hours,  this  is 
far  less  noticeable  than  when  it  is  from  nine  to  ten  hours 
during  the  day  and  fourteen  to  fifteen  hours  during  the  night. 

Colostrum  contains  less  sugar,  a  fat  very  poor  in  volatile 


COW'S   MILK.  47 

acids,  and  a  high  amount  of  nitrogenous  compounds  which 
differ  from  those  of  normal  milk. 

At  least  four  days  should  elapse  after  parturition  before 
the  milk  is  used,  although  the  milk  does  not  regain  its  normal 
composition  before  the  lapse  of  from  eight  to  fourteen  days. 
As  lactation  advances  the  fat,  casein,  and  mineral  salts  in- 
crease and  the  sugar  decreases  (the  reverse  of  what  occurs 
in  human  milk). 

The  English  Society  of  Public  Analysts  requires  the  follow- 
ing standard  in  cow's  milk:  three  per  cent,  by  weight  of  fat 
and  eight  and  a  half  per  cent,  by  weight  of  solids  not  fat. 
These  limits  have  been  accepted  as  satisfactory  by  the  great 
majority  of  analytical  chemists  in  the  country.  Vieth  has 
found  that  a  bad  season  for  haymaking  is  nearly  always  fol- 
lowed by  a  deterioration  in  the  quality  of  the  milk  in  the 
following  winter  and  spring.  Long  periods  of  cold  and  wet 
or  heat  and  drought — when  the  cattle  are  at  pasture — unfavor- 
ably influence  the  quantity  and  quality  of  the  milk.  A  limit 
of  three  per  cent,  fat  is  reasonable  for  the  mixed  milk  of  a 
whole  herd;  far  more  commonly  the  milk  falls  below  the 
standard  of  eight  and  a  half  per  cent,  of  solids  not  fat.  For 
all  practical  purposes  the  triple  standard  of  eight  and  a  half 
per  cent,  solids  not  fat,  0.5  per  cent,  total  nitrogen,  and  0.70 
per  cent,  ash  may  be  adopted  for  the  purpose  of  judging 
whether  or  not  the  milk  is  of  genuine  composition. 

Composition  of  Milk. 

Langlois 38  (French).     Soxhlet<»  (German).    Leeds93  (American). 
Per  cent.  Per  cent.  Per  cent. 

Fat 4.0  3.69  3.75 

Sugar 5.0  4.88  4.42 

Proteids 3.4  3.55  3.76 

Ash 0.6  0.71  0.68 

Total  solids 13.0                            

Water 87.0  87.17 


Ayrshire. 

Holstein. 

Jersey. 

Per  cent. 

Per  cent. 

Per  cent. 

3.89 

2.88 

5.21 

4.41 

4.33 

4.52 

4.01 

3.99 

3.99 

0.73 

0.74 

0.71 

86.96 

88.06 

85.57 

American 

grade. 
Per  cent. 

Common 
native. 
Per  cent. 

4.01 

3.69 

4.36 

4.35 

4.06 

4.09 

0.74 

0.73 

86.83 

84.14 

48  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

The  composition  of  milk  varies  considerably,  according  to 
the  breed  of  cattle.  Mr.  Gordon,  of  the  Walker- Gordon  Labo- 
ratory, has  collected  the  results  of  over  one  hundred  and  forty 
thousand  analyses,  sixty  thousand  of  which  represent  the  milk 
of  the  American  grade  of  imported  cow  and  the  common  na- 
tive. 


Durham. 
Per  cent. 

Fat 4.04 

Sugar 4.34 

Proteids 4.17 

Ash 0.73 

Water 86.72 


"  Leaving  out  the  Jerseys'  milk,  the  following  represents 
very  closely  the  average  composition  of  cow's  milk  as  the 
(American)  physician  has  to  do  with  it  in  infant  feeding" 
(Holt). 

Average  composition  of  cow's  milk  (American)  : 

Per  cent. 

Fat 3.50 

*       Sugar 4.30 

Proteids 4.00 

Ash 0.70 

Water 87.00 

Provided  the  cattle  are  healthy,  Holt  does  not  consider  that 
any  special  breed  should  be  selected  for  the  purposes  of  infant 
feeding.  As  fat  is  the  most  variable  constituent  of  milk,  the 
determination  of  its  percentage  suffices  for  all  practical  pur- 
poses. 

In  a  recent  interview  Henry  Leffmann  states  that  the  com- 
position of  good  milk  is  as  follows: 


COW'S   MILK.  49 

Per  cent. 

Fat from  3.6-4.5 

Sugar from  4. 7-4. 9 

Proteids from  3.5-3.8 

Ash from  0.7-0.8 

The  composition  of  cow's  milk  as  given  by  Droop  Eichmond 
can  undoubtedly  be  accepted  as  an  average  of  English  dairies, 
in  view  of  the  large  number  of  analyses  it  represents.  Holt's 
figures  vary  from  Eichmond's,  but  have  a  more  distinct  value 
to  the  American  physician  because  they  represent  what  might 
be  called  an  American  average  (one  hundred  and  forty  thou- 
sand cases).  The  principal  differences  between  his  figures 
and  those  of  Eichmond  consist  in  the  higher  proteid  per- 
centages. The  tables  of  Langlois,  Soxhlet,  and  Leeds  have  been 
selected  because  they  represent  the  work  of  reliable  investi- 
gators :  many  other  analyses  might  have  been  cited,  but  as 
no  two  of  them  are  identical,  their  enumeration  would  serve 
no  useful  purpose.  The  fact  cannot  be  emphasized  too  strongly 
that  the  milk  of  even  large  herds  of  cattle,  much  more  the 
milk  of  a  single  cow,  is  apt  to  vary  markedly  from  any  average 
that  can  be  established,  owing  to  differences  in  the  breed  of 
cattle,  the  methods  of  feeding,  the  season  of  the  year,  etc. 
Secondly,  no  rational  average  can  be  deduced  from  any  but  a 
large  number  of  examinations  made  under  unvarying  condi- 
tions and  with  unvarying  methods.  Finally,  no  average  can 
be  expected  to  do  more  than  establish  a  mean  which  a  good 
milk  may  reasonably  be  expected  to  approximate. 

The  figures  of  Holt  may  be  accepted  as  such  an  average, 
but  whether  the  milk  of  a  given  herd  will  resemble  it  can  be 
determined  only  by  analysis.  The  milk  of  a  carefully  fed  herd 
varies  very  little  from  day  to  day,  so  that  an  occasional  test 
is  all  that  is  necessary  to  be  assured  of  the  proportion  of  the 
different  ingredients.  It  is  a  great  advantage  of  certified  milk 
that  its  composition  has  to  satisfy  a  definite  standard,  so  that 
we  may  know  what  percentages  of  the  different  elements  we 


Solids. 

Fat 

Ash. 

3er  cent. 

Per  cent. 

Per  cent. 

13.84 

3.88 

0.85 

15.40 

6.74 

0.81 

17.13 

8.12 

0.82 

50  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

are  administering,  especially  the  amount  of  fat  present,  which 
is  the  most  variable  ingredient  in  cow's  milk. 

The  use  of  the  strippings  of  cow's  milk  in  infant  feeding 
has  been  advocated  by  some  authors.  To  illustrate  the  varia- 
tions in  its  composition,  the  following  table  is  appended: 

Harrington's  analyses : 37 


Water. 
Per  cent. 

Fore-milk 86.66 

Middle  milk 84.60 

Strippings 82.87 


Richmond  states  that  it  is  not  unusual  to  find  more  than 
ten  per  cent,  of  fat  in  strippings. 

Proteids — Albuminoids. 

Since  the  digestion  of  the  albuminoids  of  cow's  milk  consti- 
tutes one  of  the  greatest  difficulties  in  the  artificial  feeding  of 
infants,  it  seems  advisable  to  discuss  their  physical  and  chemi- 
cal properties  at  some  length.  The  consideration  of  the  other 
ingredients  follows,  while  the  various  methods  of  preparing 
milk  for  the  infant  will  be  detailed  in  a  later  chapter. 

Richmond.121  "  The  curd  of  cow's  milk  produced  by  the  ad- 
dition of  acid  is  found  to  consist  of  casein  which  is  combined 
with  phosphates  of  the  alkaline  earths.  In  human  milk  this 
is  replaced  by  a  similar  albuminoid  which  is  not  combined  with 
phosphates. 

"  Besides  casein  there  is  a  second  albuminoid  called  albumin. 
This  differs  from  casein  in  not  being  precipitated  by  acids  and 
in  being  coagulable  by  heat.  Other  albuminoids  have  been 
described  in  milk,  but  many  of  them  are  only  decomposition 
products  of  casein  or  albumin,  which  were  formed  during  the 
process  adopted  for  the  removal  of  the  other  albuminoids. 


COW'S  MILK.  51 

"  Evidence  has  been  adduced  of  a  third  albuminoid,  lacto- 
globulin.  This  is  coagulable  by  heat  and  precipitated  by  neu- 
tral sulphates,  tannin,  etc.  Eennin  does  not  coagulate  it; 
it  only  occurs  in  traces,  and  it  is  not  known  whether  it  differs 
chemically  from  serum-globulin.  The  chief  characteristic  of 
lacto-globulin  is  its  solubility  in  sodium  chloride  solutions, 
even  when  acidified. 

"  Traces  of  Storches'  mucoid-proteid  also  exist  in  milk,  and 
it  is  possible  that  traces  of  albumose  are  formed  during  the 
decomposition  to  which  milk  is  prone;  true  peptone  has  been 
proved  to  be  absent.  The  casein  in  milk  is  probably  in  the 
state  recently  described  by  Picton  and  Linder  as  pseudo-solu- 
tion. This  state  is  due  to  the  existence  of  particles  in  solution 
which  are  not  sufficiently  large  to  settle  under  the  influence 
of  gravity,  but  which  will  interfere  with  the  passage  of  light. 
They  can  be  separated  by  electricity  or  by  filtering  through  a 
porous  jar.  They  also  show  that  there  is  no  sharp  dividing 
line  between  crystalloids  and  colloids  in  solution,  substances 
in  pseudo-solution,  and  substances  in  suspension.  In  milk  we 
have  these  four  states  represented:  the  fat  is  in  suspension, 
the  casein  in  pseudo-solution,  the  albumin  in  solution  as  a 
colloid,  and  the  lactose  in  solution  as  a  crystalloid.  These 
four  states  are  probably  due  to  the  size  of  the  conglomerates 
of  molecules  or  particles." 

Properties  of  the  Albuminoids. 

"  Our  present  knowledge  of  the  albuminoids  is  far  from 
complete,  though  much  work  has  been  done  on  the  subject. 
This  is  due  to  the  fact  that  it  is  extremely  difficult  to  obtain 
these  compounds  in  anything  like  a  state  of  purity.  The 
difficulty  is  still  further  increased  by  the  peculiar  behavior 
of  casein  in  retaining  calcium  salts  if  once  it  has  been  brought 
into  contact  with  them,  as  is  the  case  in  milk. 

"  The  milk  albuminoids  are  bodies  of  complex  composition 


52  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

containing  carbon,  oxygen,  nitrogen,  hydrogen,  phosphorus, 
and  sulphnr.  The  way  in  which  these  elements  are  combined 
is  not  known.  .  .  .  The  molecule  of  albuminoids  is  very  com- 
plex, as  is  evident  by  their  being  indiffusible  bodies.  By  the 
action  of  acids  and  certain  enzymes — e.g.,  peptase  (pepsin) — 
they  are  resolved  into  simpler  bodies  which  become  more  and 
more  diffusible  as  the  decomposition  advances." 

Of  the  various  albuminoids  existing  in  cow's  milk  we  will 
describe  those  four  of  whose  presence  we  have  the  strongest 
evidence:  casein,  lactalbumin,  lacto-globulin,  and  Storches' 
mucoid-proteid. 

"  Casein  is  precipitated  by  saturating  a  solution  with  sodium 
chloride,  magnesium  sulphate,  and  ammonium  sulphate.  Glob- 
ulin is  soluble  in  a  saturated  solution  of  sodium  chloride,  but 
precipitated  by  magnesium  sulphate  and  ammonium  sulphate. 
Albumin  is  soluble  in  a  saturated  solution  of  sodium  chloride 
and  magnesium  sulphate,  but  precipitated  by  saturation  with 
ammonium  sulphate,  while  Storches'  mucoid-proteid  is  not  in 
solution. 

"  Casein  and  globulin  are  precipitated  by  acids,  while  albu- 
min (and  globulin  if  much  salt  is  present)  is  not  so  precipi- 
tated. Casein  has  the  remarkable  property  of  being  acted  upon 
by  chymase,  the  enzyme  of  rennet,  with  the  formation  of  an 
insoluble  product.  Albumin  is  coagulated  by  the  action  of 
heat,  70°  C.  being  sufficient  to  precipitate  a  great  portion. 
Casein  (and  globulin?)  are  removed  from  solution  by  filtration 
through  a  porous  cell,  while  albumin  remains  dissolved.  All 
three  are  soluble  in  alkalies  and  precipitated  by  tannin  and 
phospho-tungstic  acid  and  are  insoluble  in  alcohol." 

Casein. — "  Casein  has  the  property  of  forming  an  opalescent 
solution  when  dissolved  in  the  least  possible  excess  of  sodium 
phosphate  and  a  small  quantity  of  calcium  chloride  is  added; 
it  gives  then  a  solution  having  the  appearance  of  milk.  It  is 
probable  that  milk  contains  casein  in  this  form.  Casein  has 
a  peculiar  affinity  for  calcium  salts,  especially  the  phosphate. 


COW'S  MILK.  53 

"  Analyses  do  not  yield  very  concordant  results,  but  the  most 
probable  composition  of  casein  is  as  follows: 


Carbon.  Hydrogen.        Nitrogen.  Sulphur.       Phosphorus.        Oxygen. 

Per  cent.  Per  cent.  Per  cent.  Per  cent.  Per  cent.  Per  cent. 

53.13  7.06  15.78  0.77  0.86  22.40" 


Hammarsten's  and  Wroblewsky's  analyses  show  the  following 
differences  between  mother's  milk  casein  and  cow's  milk  casein : 


Hydro-    Nitro-  Phos-  Sul-  Oxy- 

Carbon.      gen.        gen.  phorus.  phur.  gen. 

Per          Per          Per         Per  Per  Per 

cent.        cent.        cent.  cent.  cent.  cent. 

Breast-milk  casein  (Wroblewsky)     52.24     7.72     14.97     0.68  1.17  23.66 

Cow's  milk  casein  (Hammarsten)     53.00     7.00    25.70  0.85  0.80  22.65 


Lactalbumin. — "  This  albuminoid  has  the  property  charac- 
teristic of  albumins  of  being  coagulated  by  raising  the  tem- 
perature of  its  solution  to  70°  C.  The  precipitation  is  never 
complete,  since,  according  to  Sebelien,  as  much  as  twelve  per 
cent,  may  be  left  in  solution." 

He  gives  the  following  table  of  its  composition : 


Carbon.  Hydrogen.  Nitrogen.  Sulphur.  Oxygen. 

Per  cent.  Per  cent.  Per  cent.  Per  cent.  Per-cent. 

52.19  7.18  15.77  1.73  23.13   . 


It  differs  from  casein  in  containing  no  phosphorus  and  about 
twice  as  much  sulphur.  The  amount  of  lactalbumin  in  cow's 
milk  is  variously  estimated  at  from  0.3  to  0.5  per  cent,  by 
Lehmann,  Klimmer,  and  other  investigators. 

Whey-Proteids. — When  a  solution  of  rennin  is  brought 


54  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

into  contact  with  cow's  milk  at  a  moderate  temperature  (from 
90°  to  100°  F.)  the  casein  is  coagulated  and  the  serous  portion 
of  the  milk  separates  as  a  white  translucent  fluid  called  whey. 
This  contains  the  whey-proteids,  part  of  the  salts,  the  sugar 
of  milk,  together  with  a  small  amount  of  fat.  The  whey-pro- 
teids  comprise  the  lactalbumin  and  lacto-globulin  of  milk, 
besides  a  soluble  proteid  similar  to  albumin,  which  is  split  off 
from  the  casein  by  the  action  of  the  rennin  (Leffmann). 

Both  Rotch  and  Cautley,  by  a  series  of  experiments  on  the 
coagulability  of  milk  with  acetic  acid,  have  endeavored  to  show 
that,  in  order  to  simulate  the  curd  produced  in  mother's 
milk  by  the  addition  of  acid,  cow's  milk  must  be  diluted  with 
from  four  to  five  times  its  bulk  of  water;  or,  in  other  words, 
that  there  is  from  four  to  five  times  as  much  caseinogen  in 
cow's  milk  as  in  mother's  milk.  These  results  cannot  be  ac- 
cepted as  conclusive,  for  we  know  that  coagulation  by  rennet 
is  the  first  step  in  the  digestion  of  casein  in  the  infant's  stom- 
ach; hence  the  natural  conditions  cannot  be  said  to  have  been 
imitaled  in  the  test-tube  experiments. 

Fat. 

Richmond.121  "  The  fat  in  cow's  milk  is  of  complex  com- 
position. It  differs  from  all  other  fats  in  that  it  contains 
compound  glycerides,  partly  built  up  of  fatty  acids  of  low 
molecular  weight.  The  general  consensus  of  opinion  at  the 
present  day  among  chemists  is,  that  the  fat-globules  in  milk 
are  not  surrounded  by  a  membranous  envelope,  therefore  there 
is  a  true  emulsion.  There  is  very  little  doubt  that  a  layer  of 
some  sort  exists,  probably  formed  by  a  force  similar  to  capillary 
attraction.  Leeds  says  that  this  layer  consists  of  a  number  of 
albuminous  molecules  which  have  been  condensed  by  molecular 
attraction  and  thereby  hinder  the  coalescence  of  the  fat  par- 
ticles. 

"  From  the  mean  results  obtained  by  different  observers,  the 
average  composition  of  the  fat  of  milk  appears  to  be  as  follows : 


COW'S  MILK.  55 


Per  cent.  Per  cent.             Per  cent. 

Butyrin 3.85,  yielding  3.43  fatty  acids  and  1.17  glycerol. 

Caproin 3.60,  yielding  3.25  fatty  acids  and  0.86  glycerol. 

Caprylin 0.55,  yielding  0.51  fatty  acids  and  0.10  glycerol. 

Caprin 1.90,  yielding  1.77  fatty  acids  and  0.31  glycerol. 

Laurin 7.40,  yielding  6.94  fatty  acids  and  1.07  glycerol. 

Myristin 20.20,  yielding  19.14  fatty  acids  and  2.53  glycerol. 

Palmitin 25.70,  yielding  24.48  fatty  acids  and  2.91  glycerol. 

Stearin 1.80,  yielding  1.72  fatty  acids  and  0.19  glycerol. 

Olein,  etc 35.00,  yielding  33.60  fatty  acids  and  3.39  glycerol. 

Total 100.00   Insoluble.  87.65  Total. .   12.53 

Total..  94.84 

"  Besides  the  constituents  enumerated  above,  there  also  exist 
traces  of  cholesterol  (which  doubtless  replace  a  portion  of  the 
glycerol),  lecithin,  a  coloring  matter,  and  possibly  also  a  hydro- 
carbon. % 

"  Lecithin  exists  in  small  quantities  in  butter  fat ;  on  saponi- 
fication it  gives  glyceryl-phosphoric  acid,  fatty  acids,  and  chol- 
ine; it  contains  3.84  per  cent,  of  phosphorus  and  gives  8.8 
per  cent,  of  phosphoric  acid  on  oxidation.  The  quantity  does 
not  exceed  0.5  per  cent,  of  the  fat.  There  is  also  a  coloring 
matter  of  unknown  composition  and  an  odoriferous  principle." 

Sugar. 

"  The  sugar  in  cow's  milk  is  said  to  be  not  identical  with  that 
in  human  milk.121 

"Lactose  is  not  fermentable  by  ordinary  yeast  and  is  not 
acted  upon  by  invertase,  diastase,  rennet,  pepsin,  and  trypsin. 
There  exists,  however,  an  enzyme  called  lactase,  which  is  found 
in  fresh  kephir  grains,  which  hydrolyzes  lactose  to  glucose  and 
galactose.  The  bacteria  which  decompose  lactose  with  the  pro- 
duction of  lactic  acid  are  acted  upon  inimically  by  acids,  so  that 
not  much  more  than  one  per  cent,  of  lactic  acid  is  formed  un- 
less the  solution  is  kept  neutralized." 


56 


THE   ARTIFICIAL   FEEDING   OF   INFANTS. 


Salts. 

"  The  presence  of  citric  and  acetic  acids  in  milk  has  not 
been  universally  accepted.  Bechamp  maintains  that  casein  and 
albumin  exist  in  milk  as  salts  of  alkalies.  There  is  much  to 
recommend  this  view.121 

"  Casein  has  a  peculiar  affinity  for  calcium  salts,  especially 
the  phosphates,  from  which  it  is  extremelv  difficult  to  free  it; 
nor  has  it  been  found  possible  to  dissolve  casein  to  an  appre- 
ciable extent  without  an  alkali  being  present. 

"  Milk  does  not  become  sour  until  appreciable  acidity  has 
developed.  The  phenomenon  of  coagulation  of  milk  after  this 
has  occurred,  and  on  the  application  of  heat,  is  probably  due 
io  the  acid  developed  displacing  the  casein  from  its  combina- 
tion with  an  alkali,  and,  when  this  is  wholly  accomplished, 
to  the  free  acid  manifesting  its  properties.  Soldner  has  also 
adduced  evidence  in  proof  of  this  view." 

Harrington  and  Kinnicitt.  Richmond. 

Ash  of  mother'*  milk.  Ash  of  cow's  milk. 
Per  cent.  Per  cent. 

Lime 15.69  20.27 

Magnesia 1.92  2.80 

Potash  24.77  28.71 

Soda 9.19  6.67 

Phosphoric  acid 10.73  29.33 

Chlorine   20.11  14.00 

Carbonic  acid 7.97  0.97 

Sulphuric  acid 2.19  a  trace 

Ferric  oxide,  etc 0.40  0.40 

Silica 0.70                              

Oxygen  (calculated) 6.16  .... 

99.83  103.15 

Less  oxygen  and  chlorine 3. 15 


Since  by  oxidation  the  phosphorus  and  sulphur  of  the  pro- 
teids  are  altered  into  phosphoric  and  sulphuric  acids,  and  the 


COW'S   MILK.  57 

carbon  is  changed  into  carbonic  acid,  the  ash  does  not  truly 
represent  the  mineral  constituents  of  milk.  About  eight  per 
cent,  of  the  phosphoric  acid  present  in  the  ash  is  derived  from 
the  phosphorus  of  the  casein. 

Comparison  between  the  Salts  of  Mother's  Milk  and  Cotv's 
Milk. 

Mother's  Milk.  Cow's  Milk. 

Harrington  and  Kinnicntt.  Adapted  from  Soldner. 

Per  cent.  Per  cent. 

Sodium  chloride 21.77  Sodium  chloride 10.62 

Potassium  chloride 12.05  Potassium  chloride 9.16 

Potassium  sulphate 8.33  Potassium  citrate 5.47 

Potassium  carbonate 23.47  Potassium  phosphate 21.99 

Calcium  phosphate 23.87  Calcium  phosphate 16.32 

Calcium  carbonate 2.85  Calcium  citrate 23.55 

Calcium  sulphate 2.25  Lime  combined  with  proteids  5.13 

Calcium  silicate 1.27  Magnesium  citrate 4.05 

Magnesium  carbonate 3.77  Magnesium  phosphate 3.71 

Iron  oxide  and  alumina  ....  0.37 

Leffmann  considers  that  Soldner's  table  is  in  part  theoreti- 
cal. 

Edlefsen.244  While  cow's  milk  is  richer  than  mother's  milk 
in  phosphorus,  only  the  smaller  part  of  it  is  in  organic  com- 
bination in  the  former  case.  The  remainder  is  present  as 
inorganic  phosphates.  In  woman's  milk,  on  the  other  hand, 
all  the  phosphorus  is  in  organic  combination:  according  to 
Schlossmann,  thirty-five  per  cent,  in  the  casein,  thirty-five  per 
cent,  in  the  nucleon,  and  thirty  per  cent,  in  the  lecithin,  as 
against  thirty-five  per  cent,  in  the  casein,  eleven  per  cent,  in 
the  nucleon  and  lecithin,  and  fifty-four  per  cent,  in  inorganic 
combination  in  cow's  milk.  Since  the  casein  contains  phos- 
phorus, it  may  be  considered  a  nucleo-albumin ;  but  whereas 
the  nuclein  contained  in  it  is  not  absorbable  as  such,  nucleon 


58  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

and  also  lecithin  are  very  easy  of  absorption.  The  organic 
phosphorus  combinations  are  much  more  important  for  the 
nourishment  and  growth  of  the  infant  than  the  inorganic. 
According  to  the  analyses  of  the  faeces  and  urine  by  Eohmann 
and  Steinitz,  the  administration  of  inorganic  phosphates  leads 
to  an  only  slight  gain  in  phosphorus.  In  the  proportions  in 
which  cow's  milk  is  given  to  the  infant,  there  is  only  a  small 
amount  of  casein  and  still  less  nucleoli  and  lecithin.  As  far 
as  the  nuclein  present  in  this  small  amount  of  casein  is  con- 
cerned, it  can  be  completely  absorbed.  Nuclein,  according 
to  Popoff,  and  paranuclein,  according  to  Grumlich,  Sandmeyer, 
Micko,  and  others,  are  made  soluble  by  the  pancreatic  fer- 
ments; for  the  most  part,  they  are  converted  into  nuclein- 
phosphoric  acid.  In  this  respect  there  do  not  seem  to  be  any 
essential  differences  between  cow's  milk  and  mother's  milk 
casein. 

With  regard  to  phosphorus  metabolism,  Paul  Muller  has 
shown  that  the  absorption  of  the  phosphorus  of  cow's  milk, 
when  not  introduced  in  too  large  amount,  is  just  as  complete 
as  that  of  the  phosphorus  in  mother's  milk  ( ?  Editors  ) . 
Eubner  and  Heubner  have  demonstrated  that  the  casein  of 
cow's  milk,  if  it  is  not  given  in  excess,  is  as  well  absorbed  as 
that  of  mother's  milk  (?  Editors).  But  when  diluted  cow's 
milk  is  given,  the  amount  of  organic  phosphorus  present  as 
well  as  that  of  the  organic  sulphur  in  the  lactalbumin  is  very 
small.  Up  to  the  present  we  have  found  no  means  of  com- 
pensating for  the  greater  richness  of  mother's  milk  in  nucleon 
and  lecithin,  which  increases  as  the  secretion  of  milk  becomes 
more  abundant.  We  know  also  that  boiling  destroys  the  leci- 
thin (Baginsky),  and  if  the  application  of  heat  is  prolonged, 
also  the  nucleon;  the  nuclein  of  the  casein  is  probably  also 
modified.  These  facts  perhaps  explain  why  infants  fed  for  a 
long  time  on  milk  and  milk  preparations  which  have  been  sub- 
jected for  a  considerable  period  of  time  to  excessive  heat  (such 
as  Scherff's,  Hesse's,  or  Voltmer's  Milk,  Soxhlet's  Mixture,  etc.) 


COW'S   MILK.  59 

sometimes  develop  scurvy.  The  beneficial  results  from  the 
administration  of  phosphorus  and  cod-liver  oil  in  rickets  make 
it  probable  that  this  disease  is  due,  in  great  measure  at  least, 
to  an  insufficient  amount  of  organic  phosphorus  in  the  food. 

The  diminution  of  the  percentage  of  salts  in  mother's  milk 
as  lactation  advances  is  compensated  by  the  increased  quantity 
of  the  milk  secreted;  so  that  the  total  amount  furnished  the 
infant  suffices  for  its  growth  and  especially  for  the  bony  de- 
velopment. 

Gases. 

Kichmond.121  The  gases  in  milk  have  no  practical  im- 
portance. Oxygen,  nitrogen,  and  carbon  dioxide  are  present 
when  it  is  fresh,  probably  due  to  absorption  from  the  air  during 
and  after  milking.  On  standing,  the  oxygen  decreases  and 
carbon  dioxide  increases,  probably  owing  to  aerobic  bacteria. 

Thorner  128  found  that,  directly  after  being  drawn,  cow's 
milk  contained  from  fifty-seven  to  eighty-six  cubic  centimetres 
per  litre  of  carbon  dioxide,  oxygen,  and  nitrogen.  The  serum 
of  acid  milk  contains  even  larger  amounts, — from  one  hundred 
and  fourteen  to  one  hundred  and  seventy-two  cubic  centimetres 
per  litre.  A  large  portion  of  this  gas  disappears  in  centrifuga- 
tion;  on  the  average,  from  twenty-seven  to  fifty-four  cubic 
centimetres  remain.  Boiling  and  sterilization  still  further 
reduce  the  gas  content  to  from  fifteen  to  nineteen  cubic  centi- 
metres per  litre.  By  keeping  in  closed  bottles  an  increase 
occurs,  because,  in  bottles  not  heated  directly  after  filling,  car- 
bon dioxide  fermentation  occurs.  The  unpleasant  taste  of 
milk  sterilized  in  open  bottles  depends  on  the  disappearance 
of  carbon  dioxide  and  not  on  chemical  changes.  If  carbon 
dioxide  can  be  incorporated  artificially  with  such  milk,  the 
pleasant  taste  will  return. 

Separated  Milk. 
RICHMOND.1*1     Skimmed  milk  contains  from  0.4  to  over 
two  per  cent,   fat;    in  separated  milk  the  limit  of  0.3  per 


60  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

cent,  fat  is  rarely  exceeded.  By  the  removal  of  the  fat  the 
percentage  of  the  other  constituents  is  slightly  increased. 

By  the  action  of  the  separator  a  slimy  residue  is  left  con- 
taining: (1)  Inorganic  impurities,  such  as  dirt.  (2)  Vege- 
table matter  derived  from  fodder,  such  as  hay  or  leaves.  (3) 
Substances  derived  from  the  cow,  such  as  hair,  pavement 
epithelium  from  the  udder,  empty  gland  cells  (which  form 
a  very  large  portion  of  the  slime),  numerous  micro-organisms, 
pus,  blood,  etc. 

The  quantity  of  slime  equals  0.04  part  in  one  hundred  parts 
of  milk  separated ;  in  dirty  milk  it  may  amount  to  0.15  per  cent. 

The  number  of  micro-organisms  in  cream  and  separated  milk 
is  not  appreciably  diminished  by  this  process,  and  a  mixture 
of  them  keeps  no  better  than  the  milk  from  which  they  were 
separated.  Straining  through  a  fine  wire  sieve  or  through  fine 
muslin  or  swan's  down  is  usually  practised.  This  removes  the 
grosser  impurities,  but  the  amount  of  dirt  removed  in  this  way 
does  not  exceed  0.0025  per  cent.  Filtration  through  layers  of 
gravel  or  sand  is  practised  in  some  Danish,  German,  and  Eng- 
lish dairies ;   it  has  no  advantage  over  the  previous  method. 

Variations  in  the  Composition  of  Cow's  Milk. 
Eds  all.50  In  the  course  of  metabolism  experiments  carried 
out  at  the  Pepper  Clinical  Laboratory  the  author  estimated 
the  proteids  of  milk  from  one  dairy  for  a  period  of  ten  months, 
using  the  Kjeldahl  method.  He  found  daily  variations  in  the 
proteid  content  from  2.7  to  4.1  per  cent.  These  occurred  even 
in  winter,  when  the  cows  were  given  regular  fodder;  in  the 
spring,  especially  when  the  animals  were  fed  largely  on  fresh 
grass,  the  daily  variations  were  so  great  that  calculations  based 
upon  any  fixed  percentage  were  liable  to  be  very  uncertain. 
It  will  almost  always  be  found  that  the  proportion  of  proteids 
is  below  the  commonly  accepted  four  per  cent.  In  the  same 
series  of  estimations  the  fat  percentage  varied  from  3.2  to 
nearly  six. 


CHAPTEE    IV. 
DIGESTION. 

The  digestive  tract  of  the  new-born  and  of  the  infant  pre- 
sents many  features,  both  anatomical  and  physiological,  in 
which  it  varies  materially  from  that  of  the  adult.  The  se- 
cretion of  the  different  digestive  ferments  is  slow  in  being 
established;  in  fact,  it  is  only  towards  the  end  of  the  second 
or  the  beginning  of  the  third  year  that  the  digestive  functions 
approach  in  capacity  those  of  the  fully  developed  organism. 
It  seems  advisable,  then,  for  the  proper  comprehension  of  the 
subject  of  infant  feeding,  to  consider  at  some  detail  the  anat- 
omy of  the  digestive  tract  and  the  physiology  of  the  organs 
of  digestion. 

Monti."  The  salivary  and  parotid  glands  are  small  and 
poorly  developed  at  birth,  and  the  secretion  of  the  salivary 
ferments,  according  to  most  observers,  is  slow  in  becoming 
established,  not  attaining  decided  power  before  the  period  of 
dentition.  Soltau  Fenwick  52  concludes,  on  the  basis  of  nu- 
merous experiments,  that  the  salivary  secretions  first  have  a 
decided  and  constant  influence  on  starch  about  the  fourth 
month,  and  Korowin  found  that  at  this  time  one  and  a  half 
cubic  centimetres  of  saliva  appeared  from  five  to  seven  min- 
utes after  taking  food.  On  the  other  hand,  Kriiger  asserts 
that  he  has  found  traces  of  ferment  in  the  secretions  of  the 
salivary  glands  of  a  seven  months  foetus  (Monti  and  Bagin- 
sky).  The  parotid  secretion  contains  more  diastatic  ferment 
than  the  other  salivary  glands  (Zweifel  and  Korowin"). 
While  ptyalin  is  found  in  the  parotid  at  birth  and  in  the 
submaxillary  glands  about  the  fourth  week,  the  amylolytic 
action  of  these  glands  becomes  fully  established  only  towards 

61 


62  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

the  end  of  the  first  year  (Monti,09  Thomson143).  Jacobi,78 
on  the  other  hand,  states  that  the  saliva  possesses  diastatic 
action  after  the  first  month,  although  its  secretion  is  apt  to 
be  scanty  in  the  very  young  and  in  cases  of  debility. 

The  truth  of  the  matter  would  seem  to  be  that  the  activity 
of  the  parotid  and  salivary  glands  varies  in  different  infants. 
As  a  rule,  however,  the  salivary  secretions  are  not  present  in 
sufficient  quantity  to  possess  any  considerable  diastatic  action 
on  starchy  substances  before  the  fourth  to  the  eighth  month, — 
that  is,  about  the  period  of  dentition. 

Anatomy  of  the  Stomach. 
Monti.90  The  infant's  stomach  at  first  lies  in  an  almost 
vertical  position,  and  the  fundus  is  poorly  developed;  Monti 
also  lays  stress  on  the  slight  degree  of  development  of  the 
greater  curvature.  Marfan  and  Thomson  make  similar  state- 
ments. Thomson  considers  that  the  shape  of  the  stomach  is 
originally  tubular.  The  capacity  of  the  greater  curvature 
stands  in  ratio  to  the  capacity  of  the  entire  organ  as  one 
to  five  in  the  infant,  whereas  in  adults  it  is  as  one  to  two 
(Moritz).  According  to  Fleischmann,  the  layer  of  oblique 
muscular  fibres  is  not  present  in  the  infant's  stomach,  nor 
are  the  long  fibres  described  by  Henle  which  radiate  from  the 
pyloric  valve.  The  fibres  at  the  fundus  are  the  most  poorly 
developed.  Peristaltic  movements  increase  in  strength  towards 
the  pyloric  end  of  the  stomach  and  thus  tend  to  approximate 
the  cardia  to  the  pylorus.  Although  the  musculature  is  poorly 
developed,  peristalsis  will  normally  empty  the  stomach  of  its 
contents  in  from  one  and  a  half  to  two  hours  (Leo  and  Van 
Puteren)  ;  according  to  Biedert,  in  from  two  to  two  and  a 
half  hours.  When  digestion  is  difficult,  the  time  required 
is  longer  and  evacuation  may  be  incomplete.  Vomiting  occurs 
easily,  owing  to  the  poor  development  of  the  fundus,  the  weak 
contraction  of  the  cardiac  sphincter,  and  the  fluid  consistence 
of  the  stomach  contents  (Monti).    After  ten  months  the  mus- 


DIGESTION.  63 

cular  coat  of  the  stomach  resembles  that  of  adult  life  (Mar- 
fan). 

The  lab-glands  are  less  numerous  than  in  the  adult  stomach 
(Baginsky).  Their  form  is  funnel-shaped,  and  they  are  evenly 
distributed  over  the  whole  gastric  surface.  The  multilocular 
glands  are  scattered,  being  most  numerous  at  the  p}dorus;  on 
the  other  hand,  the  mucous  glands  are  more  plentiful  than  in 
adult  life;  they  are  most  thickly  clustered  at  the  pylorus  and 
are  least  numerous  at  the  cardia  (Monti).  The  orifices  and 
lumina  of  the  gastric  glands  are  greater  than  in  adult  life; 
the  differentiation  of  the  chief  cells  and  the  parietal  cells 
occurs  at  different  times  in  different  subjects  (Marfan). 

Gastric  Capacity. 
Marfan.105  The  capacity  of  the  infant's  stomach  is  a  varia- 
ble factor,  depending  on  the  weight,  the  kind  of  food  that  is 
given,  and  the  size  of  the  child's  body.  Marfan  has  drawn 
up  an  average  table  based  on  the  figures  given  by  Beneke, 
Fleischmann,  Frolowsky,  D? Astros,  and  Zuccarelli.  The  ca- 
pacity at  birth  is  from  forty  to  fifty  cubic  centimetres;  at 
one  month,  sixty  to  seventy  cubic  centimetres ;  at  three  months, 
one  hundred  cubic  centimetres ;  at  five  months,  one  hundred 
and  fifty  to  two  hundred  cubic  centimetres;  from  six  months 
to  one  year,  two  hundred  to  two  hundred  and  fifty  cubic  centi- 
metres ;  at  two  years,  three  hundred  and  fifty  cubic  centimetres. 
These  figures  represent  average  values  and  enable  us  to  de- 
termine the  existence  of  dilatation  of  the  stomach  in  the 
cadaver.  They  have  also  been  used  as  a  basis  for  the  amount 
to  be  given  at  each  meal  in  artificial  feeding.  We  must  not 
draw  too  rigid  conclusions  from  these  figures,  for  the  capacity 
of  the  stomach  is  without  doubt  smaller  in  the  living  than 
in  the  cadaver.  Besides,  it  has  not  been  proved  that  it  is 
necessary  for  a  meal  completely  to  distend  the  stomach.  During 
nursing  a  portion  of  the  milk  ingested  probably  passes  im- 
mediately from  the  stomach  into  the  intestines. 


64 


THE   ARTIFICIAL   FEEDING    OF   INFANTS. 


Fleischmann, 
Beneke,     and 
Frolowsky,  " 
from   actual 
measurements. 

a 

o 

1 

• 

oS 
S3 

3 

as 

IP 

2   %£    • 
g§3| 

g^  J  | 

H   O 

2-3 

*  *  rf 

Cc. 

Cc. 

Cc. 

Cc. 

Cc. 

First  day 

40-45 

36 

29.4 

First  we^k 

46-50 

45 

60 

40-50 
80-90 

85-110 

70.5 

Second  week 

70-72 

Third  week 

76-105 

Fourth  week 

100-122 

90 

Sixth  week 

68 
72 

120-135 

96.6 

Eighth  week 

140-158 

100 

Tenth  week 

128 
135 

140 

118.8 

Twelfth  week 

150-167 

110 

Four  months 

160-178 

150 

150 

137.0 

125 

Five  months 

170-180 

172 

155 

158.4 

140 

Six  months 

180-200 

172 

160 

171.3 

160 

Seven  months 

206 

185.4 

180 

Eight  months 

206 

208.5 

200 

Nine  months 

244 

226.2 

238.8 

225 

Ten  months  .  v 

250 

Eleven  months 

244 

242.0 

275 

One  year , 

300-400 

267 

290 

Two  years 

600-750 

Feer.53  Examinations  of  the  cadaver  show  a  smaller  gas- 
tric capacity  than  that  commonly  accepted ;  therefore  it  is  not 
well  to  attempt  to  give  to  hand-fed  children  the  maximum 
amounts  which  infants  at  the  breast  can  take.  The  above  table 
represents  the  average  amount  which  babies  at  the  breast  will 
take.  It  should  not  be  exceeded  by  children  who  are  artificially 
fed. 

Pfaundler  225  considers  that  the  gastric  capacity  must  not 
be  compared  with  the  age  or  the  weight  of  the  infant,  since 
children  of  the  same  age  often  vary  much  in  the  degree  of 


DIGESTION.  65 

their  development,  and  since  the  change  in  the  child's  weight 
does  not  run  parallel  with  the  steadily  increasing  capacity. 
The  correct  standard  of  comparison,  according  to  this  author, 
is  the  length  of  the  child's  body,  or,  more  accurately,  the  length 
of  the  trunk.  From  the  study  of  seventy  cases  Pfaundler 
draws  these  conclusions : 

I.  The  stomach  of  children  at  the  breast  is  smaller  than 
that  of  artificially  fed  infants. 

II.  Healthy  infant  stomachs  have  a  smaller  real  capacity 
than  those  diseased  either  organically  or  functionally. 

III.  Large  stomachs  have  little  elasticity  and  distensibility, 
whereas  the  reverse  is  true  of  the  small  stomach. 

Pfaundler  found  not  a  single  instance  of  dilated  stomach 
in  children  who  were  breast-fed;  in  artificially  fed  infants 
he  found  dilatation  in  twenty  per  cent. 

We  see,  then,  that  the  gastric  capacity  is  a  variable  factor, 
depending  on  the  rapidity  of  the  child's  growth,  the  kind  of 
food  administered,  and  the  frequency  of  feeding.  The  figures 
of  Feer  and  the  measurements  of  Fleischmann,  Beneke,  and 
Frolowsky  are  high,  and  may  be  considered  maximum  amounts. 
The  tables  of  Pfaundler,  Holt,  and  Eotch  probably  represent 
the  real  capacity,  while  the  figures  based  on  measurements  of 
the  cadaver  rather  express  the  quantity  of  fluid  which  a  fully 
distended  or  partially  dilated  stomach  can  hold.  Since  our 
knowledge  of  the  anatomy  of  the  infant's  stomach  teaches  us 
that  this  organ  readily  dilates,  and  since  clinical  experience 
has  shown  that  overfeeding  (too  large  and  too  frequent  meals) 
is  only  too  common  an  occurrence,  especially  among  artificially 
fed  infants,  the  importance  of  carefully  regulating  the  size 
and  frequency  of  the  meals  cannot,  in  the  light  of  our  present 
knowledge,  be  overestimated. 

Gastric  Digestion. 
Marfan.105    Gastric  digestion  is  accomplished  by  the  gastric 
juice,  which  is  secreted  by  the  gastric  glands  and  is  composed 


66  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

essentially  of  three  substances :  ( 1 )  lab-ferment,  which  coagu- 
lates the  casein;  (2)  pepsin,  a  soluble  ferment  which  renders 
the  coagulum  soluble  and  transforms  it  into  peptone;  (3) 
chlorine  compounds,  which  unite  with  the  casein  in  process 
of  transformation,  forming  chloro-organic  compounds  analo- 
gous to  amido-acids,  and  which  can  disengage  free  hydro- 
chloric acid  when  this  transformation  is  near  its  end.  In 
the  healthy  infant's  stomach  free  hydrochloric  acid  is  absent, 
or  only  present  in  small  quantity. 

Casein  is  coagulated  by  the  lab-ferment  within  fifteen  min- 
utes of  its  entrance  into  the  stomach.  This  ferment  is  present 
already  formed  in  the  infant's  stomach,  whereas  in  the  adult 
it  exists  in  the  condition  of  a  proferment  (a  substance  analo- 
gous to  propepsin),  which  is  converted  into  lab  in  the  presence 
of  a  feebly  acid  solution.  Since  at  the  beginning  of  digestion 
the  reaction  of  the  gastric  juice  is  neutral  or  feebly  alkaline, 
coagulation  of  the  casein  is  not  due  to  the  presence  of  acids. 
All  the  casein  is  coagulated  by  the  lab;  then  a  portion  is 
attacked  by  the  combined  chlorides  and  the  pepsin,  liquefied 
and  transformed  into  peptone  (caseone  or  caseose),  which 
is  directly  absorbable;  another  portion  passes  in  a  clotted 
condition  into  the  intestine,  where  its  digestion  is  achieved 
by  the  pancreatic  juice.  On  the  other  hand,  Hammarsten  and 
Arthus  and  Pages  emphasize  the  differences  existing  between 
casein  and  albumin  with  regard  both  to  their  solubility  and 
their  digestibility.  The  action  of  lab  is  to  separate  the  soluble 
albumin  from  the  clotted  casein  with  its  lime-salt  combination. 
The  albumin  can  be  taken  up  directly  by  the  gastric  and  in- 
testinal mucous  membrane  (Briicke)  and  absorbed  without 
undergoing  further  modifications;  whereas  the  casein  is  di- 
gested principally  in  the  intestine  by  the  pancreatic  secretions. 

The  subject  of  milk  coagulation  in  the  stomach  has  recently 
been  thoroughly  investigated  by  Joseph  Schnurer  at  the  Caro- 
lina Children's  Hospital  in  Vienna.131 

According  to  this  author,  two  forms  of  coagulation  occur: 


DIGESTION.  67 

(1)  so-called   acid   precipitation    (Arthus   and   Pages),   and 

(2)  caseation  or  precipitation  by  lab-ferment    (Arthus  and 
Pages). 

1.  Acid  Precipitation. — In  this  case  the  casein  does  not  exist 
as  such,  but  in  combination  with  lime.  It  only  remains  in  this 
combination  as  long  as  there  is  present  in  the  milk  a  mixture 
of  mono-  and  di-phosphatic  salts  (especially  sodium  salts). 
When  these  salts  are  altered  by  the  addition  of  some  strong 
acid,  a  dissociation  of  the  casein-lime  combination  occurs  and 
the  casein  is  precipitated.  The  clots  resulting  from  acid  co- 
agulation are  very  fine,  soft,  and  flexible,  easily  soluble  in  weak 
alkaline  fluids,  and  can  be  curdled  again  in  this  fluid  by  the 
lab-ferment. 

2.  Caseation  or  Precipitation  by  Lab-Ferment. — In  this  pro- 
cess, according  to  Hammarsten,  casein  is  split  into  two  different 
forms  of  albumin, — paracasein  and  whey-albumin  (called  lacto- 
serum  proteose  by  Arthus  and  Pages). 

This  splitting  up  does  not  cause  the  precipitation  of  the 
paracasein,  which  first  occurs  when  sufficient  (from  0.02  to 
0.5  per  cent.)  earthy  alkaline  salts  are  present  in  the  fluid 
(calcium  chloride  being  the  best).  The  paracasein  is  then 
set  free  from  its  insoluble  casein-lime  combination.  Casea- 
tion occurs  in  coarse  lumps  taking  the  shape  of  the  test-tube. 
After  standing  the  whey  exudes  as  a  discolored  fluid  in  which 
the  whey-proteid  is  recognized  by  its  failure  to  precipitate 
with  heat  and  acid.  It  also  gives  the  biuret  reaction  after  the 
other  soluble  albumins  of  the  milk-serum,  lactalbumin  and 
lacto-globulin,  have  been  removed.  Dry  paracasein  is  with 
difficulty  soluble  in  alkalies.  Freshly  caseated  precipitated 
paracasein,  however,  can  be  dissolved  easily  in  a  weak  am- 
monia solution;  it  can  be  precipitated  out  of  such  solution 
by  soluble  lime  salts  (under  certain  conditions  of  temperature, 
etc.)  and  also  by  sodium  chloride  whether  lime  salts  are  pres- 
ent or  not,  but  paracasein  cannot  be  precipitated  by  lab- 
ferment  out  of  its  neutral  or  faintly  acid  solution,  even  in  the 


68  THE   ARTIFICIAL   FEEDING   OF   INFANTS 

presence  of  soluble  lime  salts.  This  is  the  most  important 
distinction  between  acid-casein  and  paracasein  (Hammarsten, 
Escherich,  Arthus  and  Pages). 

The  presence  of  lab-ferment  and  of  paracasein  has  been 
demonstrated  by  Arthus  and  Pages  in  experiments  on  animals 
and  with  the  stomach-tube  in  infants. 

Whether  caseation  occurs  or  not  depends  on  the  amount 
of  acid  present.  The  presence  of  lab-ferment  as  well  as  hydro- 
chloric acid  in  the  stomach  of  the  new-born  infant  has  also 
been  conclusively  demonstrated  by  Szydlowsky,  Schumburg, 
Boas,  Johnson,  Klemperer,  Arthus  and  Pages,  Kosenthal,  and 
Leo. 

Biedert  has  shown  that  the  fat  of  the  milk  acts  by  its  en- 
closure in  the  lab  clots  so  as  to  produce  much  finer  curds, 
while  Escherich  finds  that  the  fat,  by  hindering  the  spreading 
of  the  acid,  delays  its  rapid  action.  The  high  degree  of  affinity 
of  hydrochloric  acid  for  cow's  milk  seems  to  be  the  reason 
why  free  hydrochloric  acid  appears  late  or  not  at  all  in  the 
infant's  stomach  during  digestion. 

Lindenan,  Walther,  Escherich,  and  Arthus  and  Pages  agree 
that  paracasein  is  more  difficult  of  solution  in  the  stomach  than 
whey-albumin.  It  is  also  more  resistant  to  pancreatic  diges- 
tion, hence  less  well  absorbed  from  the  intestine  (Escherich). 

Marfan.105  We  know  by  the  test-tube  experiments  that  the 
casein  of  cow's  milk  clots  in  large  homogeneous  masses  which 
are  rich  in  fat  and  must  be  of  difficult  digestion;  mother's 
milk,  on  the  other  hand,  coagulates  in  fine  flakes,  poor  in  fat, 
which  are  without  doubt  more  accessible  to  the  action  of  the 
gastric  juice.  If  we  remove  the  gastric  contents  from  a  nursing 
infant  half  an  hour  after  the  meal,  we  find  that  the  chyme 
is  almost  completely  liquid  and  filters  easily,  while  at  the  end 
of  three-quarters  of  an  hour  casein  clots  are  still  present  in 
the  stomach  if  the  child  is  being  fed  on  cow's  milk.  We  may 
conclude,  then,  that  woman's  milk  is  digested  almost  entirely 
in  the  stomach,  but  cow's  milk  only  partially. 


DIGESTION.  69 

Half  an  hour  after  a  meal  the  gastric  contents  show  the 
presence  of  peptones,  whether  the  child  be  sick  or  healthy, 
and  whether  it  be  fed  on  woman's  or  cow's  milk  (Toch).  The 
casein  of  cow's  milk,  which  is  a  nucleo-albumin,  is  broken 
up  by  the  digestive  juices  into  proteoses  and  nuclein  or  pseudo- 
nuclein  (paranuclein,  according  to  Knopf elmacher,  Wroblewsky, 
and  Blauberg).  During  the  course  of  digestion  we  find  also 
ammoniacal  compounds,  leucin,  tyrosin,  and  other  by-products 
of  albuminous  digestion.  Casein,  then,  is  not  only  coagulated 
in  the  infant's  stomach,  but  it  is  also  liquefied  and  peptonized ; 
this  second  part  of  gastric  digestion  is  much  more  complete 
when  the  infant  is  nourished  at  the  breast  than  when  cow's 
milk  is  given. 

The  lactose  undergoes  in  part  lactic  acid  fermentation,  and 
helps  to  bring  about  an  acid  reaction  during  the  first  fifteen 
or  twenty  minutes  of  digestion.  The  role  of  lactic  acid  in 
gastric  digestion  is  not  yet  fully  known;  Biedert  thinks  that 
lactic  acid  can  take  the  place  of  hydrochloric  acid,  of  course 
less  efficiently.  Since  the  larger  proportion  of  the  hydrochloric 
acid  unites  with  the  casein  and  salts  of  the  milk  as  fast  as 
it  is  secreted,  the  presence  of  lactic  acid  (if  this  view  be  cor- 
rect) would  seem  beneficial  for  the  infant.  Zotow,105  on 
the  other  hand,  considers  lactic  acid  fermentation  a  sign  of 
dyspepsia,  since  he  was  never  able  to  find  lactic  acid  in  the 
stomachs  of  healthy  children.  Soltau  Fenwick  holds  the  same 
opinion. 

It  is  supposed  that  the  lactose  not  attacked  by  the  microbes 
of  lactic  acid  fermentation  is  absorbed  as  such,  or  is  split  up 
into  glucose  and  galactose,  which  are  directly  absorbable.  How 
this  is  accomplished  is  not  yet  definitely  established,  whether 
by  the  action  of  hydrochloric  acid,  or  microbes,  or  of  a  special 
ferment  (lactase).  It  is  certain  that  the  lactose  is  absorbed 
under  one  form  or  other  almost  entirely  by  the  stomach;  a 
minimal  part  is  absorbed  from  the  intestine. 

The  greater  portion  of  the  salts  is  absorbed  by  the  stomach, 


70  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

besides  most  of  the  water  taken  into  the  economy ;  von  Mering 
alone  asserts  that  the  latter  passes  altogether  into  the  intes- 
tine. The  fats  are  not  modified  in  the  stomach;  they  enter 
the  intestine  either  free  or  imprisoned  in  the  casein  clots. 

We  can  divide  gastric  digestion  into  three  phases.  In  the 
first,  which  lasts  about  half  an  hour,  the  lab-ferment  coagulates 
the  casein  in  the  presence  of  a  neutral  or  alkaline  reaction. 
In  the  second  the  reaction  of  the  chyme  becomes  acid;  lactic 
acid  is  formed,  and  the  casein  unites  with  the  chlorides  of  the 
gastric  juice;  in  the  third  phase  the  stomach  is  emptied  by 
peristalsis;  then  and  then  only  do  we  find  the  reactions  de- 
noting the  presence  of  free  hydrochloric  acid. 

Hayem  and  Winter  105  made  a  special  study  of  the  chemistry 
of  the  gastric  juice  in  infants.     They  conclude  that : 

1.  The  total  acidity  is  feeble;  it  is  due  to  lactic  acid,  and 
especially  to  hydrochloric  acid  in  combination  with  organic 
matters  and  ammonia. 

2.  The  total  chlorides  are  small  in  quantity,  which  indicates 
either  that  the  secretory  apparatus  is  but  slightly  developed 
in  the  infant  or  that  there  is  only  a  feeble  response  to  the 
stimulus  of  milk  entering  the  stomach. 

3.  After  half  an  hour  the  digestion  of  a  test-meal  is  about 
as  advanced  as  it  would  be  in  the  adult  after  one  hour. 

Marcel  and  Henry  Labbe  108  have  shown  that : 

1.  In  infants  under  two  years  the  gastric  juice  never  con- 
tains free  hydrochloric  acid  during  digestion. 

2.  The  fixed  chlorides  exist  in  quite  definite  proportions; 
their  quantity  increases  rapidly  during  the  first  months  of 
life,  to  attain  a  maximum  at  one  year  and  then  decrease. 

3.  The  combined  chlorides  and  the  total  chlorides  increase 
with  the  age  of  the  child. 

4.  The  total  acidity,  feeble  in  the  new-born,  increases  very 
rapidly  during  the  first  months  of  life,  owing  to  fermentation 
in  the  stomach ;  later  it  increases  more  slowly  parallel  with  the 
combined  chlorides. 


DIGESTION.  71 

Marfan.105  We  find  a  higher  total  acidity  when  healthy 
infants  are  fed  on  pure  cow's  milk;  this  acidity  is  due  not 
to  free  hydrochloric  acid,  but  to  lactic  acid  (which  is  formed 
in  greater  abundance  than  when  the  infant  is  fed  on  mother's 
milk)  and  to  combined  chlorides,  which  are  also  present  in 
larger  quantities.  The  percentage  of  total  chlorides  is  also 
higher;  it  reaches  a  figure  at  the  end  of  three-quarters  of  an 
hour  almost  equal  to  that  in  the  adult  one  hour  after  the  test- 
meal.  But  the  ratio  of  the  total  chlorides  to  the  fixed  chlorides 
is  rather  inconstant,  sometimes  higher  and  sometimes  lower, 
indicating  anomalies  in  the  gastric  chemistry  which  are  in 
accord  with  the  exaggerated  elevation  of  «•  •  -  -^j- .  A  =  the 
degree  of  total  acidity ;  H  =  free  hydrochloric  acid ;  C  =  the 
combined  chlorides.  The  elevation  of  a  indicates  an  excess 
of  acids  of  fermentation.  These  characteristics  can  be  con- 
sidered as  the  effect  of  a  certain  degree  of  gastritis  with  rela- 
tive hyperpepsia  and  abnormal  fermentations. 

All  authors  are  agreed  in  recognizing  that  free  hydrochloric 
acid  is  absent  from  the  chyme  during  gastric  digestion  of  milk, 
whether  the  infant  be  sick  or  healthy;  but  there  is  disagree- 
ment on  the  question  whether  hydrochloric  acid  does  not  ap- 
pear towards  the  end  of  digestion  or  after  the  evacuation  of 
the  stomach  contents.  According  to  Eeichmann,  Leo,  Cassel 
and  Heubner,  Wohlmann,  and  A.  Czerny,  hydrochloric  acid  ap- 
pears near  the  end  of  digestion  or  after  the  evacuation  of  the 
stomach  contents.  In  breast-fed  babies  A.  Czerny  found  hydro- 
chloric acid  in  the  stomach  one  and  a  quarter  hours  after  taking 
food,  to  attain  its  maximum  in  from  one  and  a  half  to  two 
hours  afterwards;  in  the  artificially  fed  child  hydrochloric 
acid  appeared  only  about  two  hours  after  the  meal.  Einhorn 
and  Hayem  found  no  free  hydrochloric  acid.  Thiercelin  did 
not  find  free  hydrochloric  acid  in  healthy  infants;  it  was, 
however,  occasionally  present  in  dyspeptic  children. 

The  absence  of  free  hydrochloric  acid  is  explained  by  the 
fact  that  during  digestion  a  large  portion  of  it  enters  into 


72  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

combination  with  the  casein  and  phosphatic  salts  of  the  milk; 
this  also  shows  why  its  appearance  is  longer  delayed  in  the 
digestion  of  cow's  milk. 

Lactic  acid  is  present  during  the  first  half-hour  of  digestion, 
and  after  that  time  hydrochloric  acid  (Uffelmann,  Ewald, 
Boas).  Heubner  has  estimated  the  quantity  of  lactic  acid 
present  to  be  from  0.10  to  0.40  per  cent. 

Bauer  and  Deutsch  17  have  investigated  the  gastric  secre- 
tions in  a  large  number  of  children.  Of  these  eight  were  in- 
fants, five  under  five  months,  three  over  five  months  old, — 
all  of  them  healthy.  The  latter  were  fed  on  pure  cow's  milk,  the 
former  on  pure  cow's  milk  and  water,  equal  parts.  In  from 
three-quarters  of  an  hour  to  one  hour  and  a  half  after  food 
ingestion  lactic  acid  was  always  found  in  large  amounts;  the 
total  acidity  was  feeble.  Free  hydrochloric  acid  could  not  be 
demonstrated  in  the  younger  infants.  In  the  three  cases 
over  five  months  of  age  they  obtained  from  0.06205  to 
0.08395  per  cent,  free  hydrochloric  acid  after  from  one 
and  a  half  to  two  hours.  They  conclude  that  during  the 
first  months  of  life  lactic  acid  predominates,  especially  at  the 
beginning  of  digestion.  During  the  second  half  of  the  first 
year  the  percentage  of  free  hydrochloric  acid  increases  and  is 
approximately  similar  to  that  found  in  adults.  The  reaction 
of  the  empty  stomach  was  found  to  be  neutral  or  acid,  the 
presence  of  secretion  being  due  to  irritation  by  the  stomach- 
tube.  The  specific  gravity  of  the  gastric  juice  varied  from 
1005  to  1009.  Experiments  were  made  to  determine  the  power 
and  rapidity  of  absorption  by  the  stomach.  Potassium  iodide 
was  detected  in  the  saliva  in  from  four  to  seven  minutes  after 
its  ingestion,  and  in  the  urine  in  from  seven  to  fifteen  min- 
utes, somewhat  earlier  than  is  the  case  in  adults,  while  the 
salol  test  gave  positive  results  usually  in  from  thirty  to  thirty- 
five  minutes.  Butyric  and  acetic  acids  could  not  be  demon- 
strated. 

The  gastric  secretions  of  three  premature  infants  were  also 


DIGESTION.  73 

studied ;  only  minimal  amounts  of  acid  could  be  demonstrated. 
Lactic  acid  was  always  present,  but  free  hydrochloric  acid  was 
not  demonstrable.    Wohlmann  obtained  similar  results. 

Nine  healthy  children,  varying  in  age  from  two  and  a  half 
to  ten  years,  showed  in  the  great  majority  of  the  cases  the 
presence  of  free  hydrochloric  acid  from  one  to  one  and  a  half 
hours  after  taking  food;  the  quantity  varied  from  0.04015 
to  0.12957  per  cent.  At  the  beginning  of  digestion  lactic  acid 
predominated,  later  hydrochloric  acid.  There  was  a  marked 
antagonism  between  hydrochloric  and  lactic  acids.  The  motor 
power  and  power  of  absorption  of  the  stomach  showed  little 
variation  from  the  conditions  present  in  the  adult.  Lactic  acid 
was  found  ten  minutes  after  taking  food;  it  increased  in 
quantity  during  the  next  thirty  to  forty  minutes,  to  dis- 
appear gradually  with  the  appearance  of  hydrochloric  acid. 
We  have,  then,  three  stages  of  digestion :  ( 1 )  lactic  acid  alone, 
(2)  lactic  and  hydrochloric  acids  both  present,  (3)  hydro- 
chloric acid  alone. 

In  infants  suffering  from  gastro-intestinal  disorders  the 
presence  of  free  hydrochloric  acid  could  not  be  demonstrated. 
Lactic  and  butyric  acids  were  found  in  considerable,  and  acetic 
acid  occasionally  in  smaller,  quantity.  Where  the  disease  was 
confined  to  the  intestines,  free  hydrochloric  acid  was  sometimes 
present.    Motility  and  absorption  were  much  delayed. 

Cohn  investigated  for  the  presence  of  free  hydrochloric  acid 
by  Mintz's  method  in  eighty  cases ;  all  of  them  were  breast-fed 
and  suffering  from  a  variety  of  gastro-intestinal  disturbances, 
of  which  eleven  were  acute  and  sixty-nine  subacute  and  chronic 
disorders.  Free  hydrochloric  acid  could  be  demonstrated  in 
only  fourteen  out  of  ninety-four  investigations;  the  largest 
quantities  found  were  0.13,  0.1,  and  0.062  per  cent.  The  tests 
were  carried  out  one  and  a  half,  two,  and  two  and  a  half  hours 
after  nursing. 

Wolf  and  Fried jung  157  have  studied  the  secretions  of  the 
stomach  in  ninety-eight  cases,  varying  in  age  from  ten  days 


74  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

to  twenty-one  months,  and  suffering  from  various  acute  and 
chronic  gastro-intestinal  diseases.  They  conclude  that  the 
presence  or  absence  of  the  normal  secretions  of  the  stomach 
is  not  a  reliable  test  of  the  powers  of  digestion. 

Bauer  and  Deutsch.17  The  views  of  authors  are  consider- 
ably at  variance  with  regard  to  the  kind  of  acid  predominating 
in  the  infant's  stomach  during  digestion.  Biedert,  Wohlmann, 
Moncorvo,  and  others  consider  hydrochloric  acid  the  domi- 
nating factor ;  on  the  other  hand,  Heubner,  Van  Puteren,  Mas- 
sing and  others  emphasize  the  presence  of  lactic  acid.  Gener- 
ally they  found  hydrochloric  acid  present  only  in  isolated  cases ; 
this  must  be  ascribed  (in  accordance  with  Leo's  statement) 
to  the  power  of  milk  to  combine  with  and  neutralize  acids. 

Leo  obtained  a  faintly  acid  reaction  one-quarter  of  an  hour 
after  milk  was  ingested ;  at  the  end  of  digestion  a  small  amount 
of  free  hydrochloric  acid  could  sometimes  be  demonstrated. 
Van  Puteren  found  after  ten  minutes"  digestion  a  total  acidity 
of  0.878  per  cent.,  with  maximum  values  of  from  one  to  2.1 
per  cent.  Von  Jaksch,  in  a  three-weeks-old  infant,  found  a 
total  acidity  of  0.512  per  cent,  after  one  hour's  digestion. 
Einhorn  obtained  an  acid  reaction  after  one  hour,  but  could 
not  demonstrate  the  presence  of  free  hydrochloric  acid.  Heub- 
ner  was  able  to  determine  quantitatively  the  presence  of  free 
hydrochloric  acid  after  from  one  and  a  half  to  two  hours' 
digestion  in  the  great  majority  of  his  observations;  in  a  less 
advanced  stage  of  digestion  he  almost  invariably  found  lactic 
acid  present.  Copolt  determined  the  presence  of  free  hydro- 
chloric acid  only  exceptionally;  in  contrast  to  this,  he  found 
the  total  acidity  to  vary  from  0.02  to  0.08  per  cent.  On  the 
other  hand,  Wohlmann's  figures  for  free  hydrochloric  acid  are 
high.  He  found  from  0.831  to  1.08  per  cent,  present  in  from 
one  and  a  quarter  to  two  hours  after  taking  food.  Marcel  and 
Henry  Labbe  obtained  the  following  figures  at  different  ages, 
representing  the  degree  of  total  acidity :  in  the  new-born  0.03 
per  cent.;    from  one  to  six  months  0.11  per  cent.;    from  six 


DIGESTION.  75 

months  to  one  year  0.13  per  cent. ;  from  one  to  two  years  0.14 
per  cent. 

W.  Soltau  Fenwick  52  instituted  a  series  of  experiments  on 
healthy  infants,  some  breast-fed,  others  getting  cow's  milk  or 
farinaceous  food.  The  tests  were  identical  in  method  and  the 
same  quantity  of  food  was  given  each  time. 
t  I.  The  amount  of  hydrochloric  acid  secreted  varies  in  differ- 
ent children  and  in  the  same  child  from  day  to  day  and  from 
meal  to  meal.  In  the  stomach  of  nursing  infants  milk  is 
usually  curdled  in  from  ten  to  fifteen  minutes  after  its  en- 
trance, owing  to  the  presence  of  lab-ferment  in  the  gastric 
secretion.  This  is  observed  immediately  after  birth.  The  acid- 
ity of  the  gastric  contents  gradually  increases  during  digestion, 
and  attains  its  maximum  in  from  ninety  to  one  hundred  and 
ten  minutes  after  the  commencement  of  the  meal.  The  average 
total  acidity  is  0.02  per  cent,  at  the  end  of  ten  minutes, 
from  0.06  to  0.075  per  cent,  at  the  end  of  one  hour,  and  0.13 
per  cent,  at  the  end  of  eighty  minutes.  (N.B. — Ordinary 
methods  of  filtration  reduce  the  acidity  of  the  gastric  contents, 
often  by  as  much  as  0.05  per  cent.)  Free  hydrochloric  acid 
is  an  inconstant  factor,  appearing  usually  after  eighty  minutes, 
or  when  the  viscus  is  partially  empty.  Pepsin  is  invariably 
present  so  long  as  the  secretion  contains  any  trace  of  the  min- 
eral acids.  Lactic  and  other  secondary  acids  are  not  found 
in  normal  digestion,  and  must  be  regarded  as  evidence  of 
fermentation. 

II.  When  the  infant  is  fed  on  cow's  milk  the  total  gastric 
acidity  is  greater,  and  may  amount  at  the  end  of  eighty  min- 
utes to  0.18  per  cent,  of  hydrochloric  acid.  Free  hydrochloric 
acid  can  usually  be  found  near  the  end  of  digestion.  In  most 
cases  lactic  acid  can  also  be  detected,  but  never  in  any  ap- 
preciable amount. 

III.  When  the  diet  is  farinaceous,  the  total  acidity  of  the 
gastric  contents  is  invariably  diminished,  and  may  not  exceed 
more  than  half  the  normal.     In  a  few  cases  eighty  minutes 


76  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

after  giving  oatmeal  and  water  there  was  only  faint  acidity. 
The  same  children  showed  normal  powers  of  secretion  when 
given  milk. 

The  quantity  of  gastric  juice  secreted  bears  a  distinct  rela- 
tion to  the  kind  of.  food  and  the  size  of  the  meal.  The  proteid 
elements  of  the  milk  seize  on  the  free  acids  and  fix  them  in  a 
chemical  combination.  Pfungen  has  shown  that  one  hundred 
grammes  of  milk  can  saturate  0.298  gramme  of  hydrochloric 
acid;  Liittke,  that  this  combination  is  stable  at  high  tempera- 
tures, and  does  not  give  the  usual  reaction  of  free  acid.  Free 
acid  is  not  found  until  all  the  proteids  have  been  saturated, 
hence  appears  late  or  not  at  all.  Bacterial  growth  is  thus  not 
inhibited  to  any  extent.  Fenwick  found  that  the  stomach 
emptied  itself  at  the  end  of  one  and  a  half  hours  (on  the 
average)  in  breast-fed  children  and  in  those  fed  on  cow's  milk 
at  the  end  of  two  and  a  quarter  hours;  in  all  cases  the  major 
portion  of  its  contents  disappeared  within  the  first  hour. 
About  forty-five  minutes  longer  were  required  to  dispose  of 
the  last  thirty  to  forty  cubic  centimetres.  Peptone  can  always 
be  recognized  within  half  an  hour  of  the  ingestion  of  food, 
proving  the  stomach  to  be  more  than  a  mere  reservoir. 

After  the  food  leaves  the  stomach  there  still  remains  a  small 
amount  of  mucus  and  gastric  juice,  in  which  free  hydrochloric 
acid  can  be  recognized.  Pfannenstill  has  shown  by  the  salol 
test  that  the  motor  activity  of  the  stomach  is  not  less  than  in 
older  children.  Salicyluric  acid  appears  in  the  urine  within 
the  normal  time. 

Summary. 

It  would  appear  from  these  rather  discordant  observations 
that  during  the  early  months  of  life  the  secretions  of  the 
stomach — namely,  those  of  hydrochloric  acid  and  pepsin — are 
deficient  in  quantity  when  compared  with  those  of  a  healthy 
adult.  Lab-ferment  seems,  as  a  rule,  to  be  present  in  sufficient 
amount,  but  the  hydrochloric  acid  combines  with  the  albu- 
minoids of  the  milk  as  fast  as  it  is  poured  out,  so  that  it  is 


DIGESTION.  77 

only  at  the  end  of  digestion,  if  at  all,  that  we  find  free  hydro- 
chloric acid.  Lactic  acid,  on  the  other  hand,  is  present  almost 
from  the  first,  owing  to  the  splitting  up  of  the  lactose  furnished 
in  the  nourishment.  While  the  secretion  of  hydrochloric  acid 
seems  to  be  sufficiently  plentiful  for  the  needs  of  the  healthy 
breast-fed  infant,  it  would  seem  that  the  artificially  fed  child 
requires  more  hydrochloric  acid  for  the  purposes  of  digestion, 
owing  either  to  the  greater  saturating  power  for  acids  of  the 
casein  of  cow's  milk  or  to  the  greater  preponderance  of  the 
albuminoids  in  the  latter.  Hence  comes  the  greater  frequency 
of  gastric  fermentation  in  bottle-fed  babies,  since  the  normal 
bactericidal  action  of  the  hydrochloric  acid  is  feeble  or  absent. 
No  standard  can  be  formulated  for  the  amount  of  free  hy- 
drochloric acid  present  normally  during  digestion;  but  it 
must  be  accepted  as  established  that  free  hydrochloric  acid 
is  an  inconstant  factor,  rarely  found  in  considerable  quantity. 
Lactic  acid  fermentation  seems  to  be  a  part  of  normal  diges- 
tion. 

Marfan.105  The  time  of  gastric  digestion  varies  in  different 
subjects  and  according  to  the  kind  of  food  given.  Generally 
it  may  be  said  that  in  the  healthy  nursing  child  the  stomach 
is  emptied  from  one  and  a  half  to  two  hours  after  the  meal; 
if  the  child  is  fed  on  boiled  or  sterilized  cow's  milk  the  time 
required  will  be  from  two  to  three  hours;  while  raw  cow's 
milk  does  not  leave  the  stomach  until  four  hours  after  its 
administration,  according  to  Eeichmann. 

The  muscular  wall  of  the  stomach  is  relatively  thin  during 
the  early  months  of  life  and  peristaltic  movements  are  doubt- 
less feeble  in  the  new-born.  But  woman's  milk,  after  the 
coagulation  of  the  casein,  remains  almost  liquid;  it  can  be 
digested  without  being  churned  in  the  stomach ;  it  is  evacuated 
the  more  easily  into  the  intestine  since  it  is  assisted  by  gravity, 
the  position  of  the  stomach  being  nearly  vertical.  When  the 
child  is  nourished  with  cow's  milk,  the  volume  of  the  clots 
must  increase  the  difficulty  of  peristalsis.     This  is  doubtless 


78  TBB-ftKTlFIClAi,   FEEDING   OF   INFANTS. 

one  of  the  causes  of  the  tardy  and  ihrperfect  digestion  of 
cow's/milk  by  the  infant.  ( 

Intestinal  Digestion. 
fhe  water  which  has  not  been  absorbed  by  the  stomach  en- 
teris  the  duodenum  in  successive  jets  mixed  with  the  mucus 
of/  the  chyme.  The  casein  leaves  the  stomach  partly  in  the 
form  of  small  clots  but  slightly  modified,  partly  as  syntonin, 
(ropep^one,  peptones,  besides  compounds  of  chlorine  and  am- 
tna^fatty  acids,  leucin,  tyrosin,  and  gases  (chiefly  carbon 
ffidxide).  Only  a  small  amount  of  lactose  enters  the  intes- 
tine; part  of  it  has  been  absorbed  from  the  stomach;  proba- 
bly part  passes  into  the  intestine  as  lactic  acid.  The  fat  is 
not  modified  as  it  leaves  the  stomach;  a  part  is  in  suspension 
in  the  fluid,  a  part  is  incorporated  in  the  casein  clots.  The 
salts  which  are  not  in  solution  are  probably  for  the  most  part 
incorporated  in  the  casein  clots.  The  whole  has  an  acid  re- 
action as  it  enters  the  duodenum,  where  it  is  subjected  to  the 
action  of  the  bile,  the  pancreatic,  and  the  intestinal  juices. 

Anatomy  of  the  Intestinal  Tract. 
Normally,  the  abdomen  of  the  infant  is  rather  prominent 
and  voluminous;  besides  this,  the  lumbar  spine  is  almost 
straight  and  not  curved  as  in  the  adult  (Marfan).  The  length 
of  the  intestinal  canal  is  more  than  six  times  that  of  the 
body.  Frolowsky  states  that  the  relative  length  of  the  large 
as  compared  with  the  small  intestine  equals  in  the  new-born 
one  to  six,  in  infants  one  to  five,  and  in  the  adult  one  to  four. 
The  muscular  coat  of  the  intestines  is  relatively  poorly  de- 
veloped, peristalsis  is  irregular  and  inclined  to  be  sluggish, 
and  there  is  a  tendency  to  dilatation  of  the  abdomen  (Monti). 
The  duodenum  forms  a  ring  instead  of  the  horseshoe  curve 
of  adult  life  (Marfan).  It  is  proportionately  longer  than  in 
adults,  and  its  second  portion  constitutes  a  reservoir  in  which 
the  bile  and  pancreatic  juices  can  accumulate.     The  caecum 


DIGESTION.  79 

lies  high  in  the  abdomen.  The  sigmoid  flexure  is  very  long, 
representing  at  birth  nearly  half  the  large  intestine;  it  is 
very  sinuous,  and  lies  almost  altogether  outside  the  very  nar- 
row pelvic  cavity.105  We  note  in  the  anatomy  of  the  intes- 
tines: the  feeble  development  of  the  muscular  wall,  the  rela- 
tively advanced  development  of  the  mucosa,  especially  of  the 
lymphoid  elements,  the  great  vascularity  of  the  villi,  and  the 
richness  in  nerves  imperfectly  myelinized.105  Lieberkiihn's 
glands  are  less  numerous  than  in  the  adult ;  the  mucous  glands, 
on  the  contrary,  are  very  plentiful  and  their  secretion  is  copi- 
ous." Brunner's  glands,  though  numerous,  are  in  the  early 
stage  of  their  development.105 

The  development  and  vascularity  of  the  villi  and  the  almost 
complete  evolution  of  the  lymphatic  tissues  furnish  conditions 
favorable  for  the  absorption  of  chyle.  Since  the  secretory 
apparatus  is  less  developed,  the  food  must  be  easy  of  di- 
gestion. The  characteristics  of  the  nervous  tissues  explain 
the  readiness  with  which  the  intestines  respond  to  causes  of 
irritation  and  the  ease  with  which  this  excitability  becomes 
exhausted.105 

Baginsky  considers  that  the  connective-tissue  corpuscles  of 
the  mucosa  form  part  of  the  lacteal  system  which  begins  at 
the  terminal  processes  of  the  papillae ;  they  constitute,  together 
with  the  large  lymph-paths  of  the  intestine,  the  real  absorbent 
system  (Baginsky).  Histological  investigation  has  shown  that 
the  absorptive  power  of  the  intestinal  tract  in  infancy  is  essen- 
tially greater  and  more  developed  than  that  of  adults,  but  phys- 
iological and  chemical  activity  is  less  than  in  those  of  mature 
age  because  the  glands  are  relatively  poorly  developed.  On 
account  of  the  extent  and  development  of  the  absorbent  lymph- 
paths,  the  intestine  of  the  infant  will  easily  absorb  all  the 
nutrient  material  which  can  be  taken  up  without  marked  chemi- 
cal change,  whereas  all  food  products  which  require  marked 
chemical  alteration  can  be  utilized  but  slightly,  if  at  all  (Ba- 
ginsky). 


80  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

Marfan.105  At  birth  the  pancreas  possesses  its  normal  form 
and  structure;  its  size  is  considerable;  it  weighs  thirty-two 
grammes, — that  is  to  say,  y-J-g-  part  of  the  weight  of  the  body ; 
whereas  in  the  adult  it  weighs  from  eighty  to  one  hundred 
grammes, — that  is  to  say,  about  -g^  part  of  the  body  weight. 
The  pancreatic  juice  contains  three  ferments:  trypsin,  which 
in  an  alkaline  medium  transforms  albuminoids  into  peptones; 
ptyalin  or  amylopsin,  which  saccharines  starch;  and  steapsin, 
which  emulsifies  the  fats.  Trypsin  is  present  from  birth  and 
even  during  foetal  life  (Albertoni,  Langendorff,  Hammarsten), 
but  its  secretion  is  scanty  in  the  first  weeks.  Steapsin  is  also 
present  from  the  first;   not  so  the  saccharifying  ferment. 

According  to  Korowin,  amylopsin  is  absent  up  to  the  twen- 
tieth day,  and  only  traces  are  present  till  the  fourth  month; 
from  the  sixth  month  the  saccharifying  power  is  definitely 
established.  Zweifel  found  the  pancreatic  extract  without 
power  to  act  on  starch  up  to  the  eighteenth  day;  Krueger 
obtained  similar  results  in  experiments  on  new-born  animals. 
E.  Moro  claims  to  have  found  traces  of  the  saccharifying  fer- 
ment in  the  pancreas  of  the  new-born.  We  may  conclude  that 
this  ferment  is  absent  or  exists  only  in  very  small  quantities 
during  the  first  period  of  the  infant's  life.  Since  milk  con- 
tains no  starch,  the  young  child  has  no  need  of  this  ferment; 
but  one  can  readily  understand  the  dangers  of  administering 
starchy  foods  to  infants  before  the  close  of  the  first  year. 
Zweifel  states  that  in  robust  infants  the  trypsin  ferment  can 
digest  albuminoids  even  in  the  first  month;  the  power  to 
split  up  neutral  fats  exists,  however,  only  to  a  slight  degree 
in  infancy. 

The  liver  is  more  voluminous  than  in  the  adult. 

Bile  forms  the  larger  part  of  the  meconium,  and  is  present 
from  the  third  month  of  foetal  life.  The  total  quantity  of 
bile  secreted  by  the  new-born  and  the  infant  is  relatively  more 
considerable  than  the  amount  secreted  by  the  adult.  During 
infancy  the  bile  is  deficient  in  fat,  organic  salts,  and  choles- 


DIGESTION.  81 

&rin,  and  especially  poor  in  biliary  acids  (Jacubowitsch,  con- 
firmed by  Baginsky  and  Sommerfeld)  ;  mineral  salts,  except 
iron,  are  present  in  small  amounts;  bilirubin  and  biliverdin 
are  abundant. 

Bile  does  not  seem  to  have  any  powerful  influence  on  di- 
gestion, but  it  helps  to  hold  the  fats  in  emulsion.  Its  anti- 
septic power  is  feeble.  The  deficiency  in  biliary  acids  explains 
the  inability  of  the  infant  to  digest  food  too  rich  in  fat,  also 
the  ease  with  which  bacterial  growth  and  intestinal  putrefaction 
occur  (if  the  other  conditions  are  favorable). 

Baginsky  thinks  that  the  deficiency  in  biliary  acids  favors 
pancreatic  digestion,  since  the  latter  will  not  occur  in  too  acid  a 
medium.  In  the  intestine  cholesterin  is  neither  absorbed  nor 
modified,  but  is  eliminated  as  such  by  the  faeces.  The  biliary 
salts  are  decomposed  in  the  intestine  into  amido-acids  (taurin 
and  glycocol)  and  a  cholic  nucleus  (base).  The  former  are  re- 
absorbed almost  entirely  and  returned  to  the  liver ;  the  latter  is 
in  part  reabsorbed  and  in  part  eliminated  by  the  faeces.  Mi- 
crobes probably  are  responsible  for  the  splitting  up  of  the  bile 
salts,  for  in  the  intestine  of  the  foetus  where  germs  are  absent 
we  find  unaltered  taurocholic  acid  (Zweifel).  In  the  meco- 
nium before  birth  the  normal  biliary  pigments  are  found  in 
an  unaltered  condition,  also  a  red  pigment  due  to  oxidation 
(Zweifel).  In  the  intestine  of  the  new-born  and  nursing  in- 
fant there  is  only  partial  reduction  of  the  normal  pigments, 
so  that  we  find  at  the  same  time  bilirubin  and  hydro-bilirubin. 
In  pathological  conditions  the  stools  contain  a  further  product 
of  oxidation, — namely,  biliverdin  (green  stools). 

The  secretion  of  the  intestinal  glands  is  alkaline  and  pos- 
sesses only  feeble  digestive  properties.  Its  principal  function 
is  to  alkalize  the  chyle  and  thus  further  absorption  and  in- 
crease peristalsis.  Miura  has  found  in  the  intestine  of  the 
foetus  and  the  new-born  a  ferment  capable  of  converting  cane- 
sugar;  other  authors  claim  to  have  discovered  a  saccharifying 
ferment, — namely,  lactase.    Moro  discovered  a  diastatic  enzyme 

6 


82  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

which  was  present  in  the  intestinal  contents  and  in  the  fasces, 
as  a  rule,  directly  after  birth;  during  the  first  weeks  of  life 
it  increased  rapidly  in  quantity.  This  diastatic  enzyme  is 
secreted  by  the  glandular  organs  of  the  intestine,  and  traces 
of  the  same  can  be  demonstrated  in  the  extract  of  pancreas 
of  the  new-born.  Bacteria,  on  the  other  hand,  have  no  share 
in  its  production.  Woman's  milk  normally  contains  an  enzyme 
of  intense  saccharifying  properties,  which  is  not  present  in 
cow's  milk.  This  enzyme  can  be  found  in  the  fasces  of  nursing 
infants,  and  considerably  increases  their  diastatic  properties. 
Marfan  has  found  a  fat-splitting  ferment  (lipase)  in  mother's 
milk,  which  is  very  active.  It  is  also  present  in  cow's  milk, 
but  is  less  active. 

When  infants  are  nursed  at  the  breast,  the  gastric  chyme 
reaches  the  duodenum  with  portions  of  the  casein  transformed ; 
its  acidity  is  feeble,  and  the  undigested  clots  are  very  fine,  so 
that  trypsin  can  act  rapidly  and  easily.  This  ferment  liquefies 
the  coagulated  casein  and  converts  it  into  anti-peptone,  which 
is  absorbed  as  such,  and  hemi-peptone,  which  after  prolonged 
pancreatic  digestion  is  broken  up  into  amido-acids  (leucin, 
tyrosin,  and  hypoxanthine)  and  other  by-products.  When  in- 
fants are  fed  on  cow's  milk,  the  digestion  of  casein  in  the 
stomach  is  much  less  advanced.  The  chyme  is  more  acid  and 
the  clots  larger  and  more  difficult  of  penetration,  so  that  the 
pancreatic  digestion  of  the  albuminoids  is  slow  and  imperfect. 

Lactose  enters  the  intestine  partly  as  such,  partly  as  lactic 
acid.  The  lactose  may  be  absorbed  as  such,  or  may  be  split 
up  by  the  action  of  micro-organisms  into  galactose  and  glu- 
cose, which  can  be  directly  absorbed.  Others  think  that  lactase 
is  responsible  for  this  change.  Undoubtedly  a  portion  of  the 
lactose  undergoes  lactic  acid  fermentation  in  the  intestines. 
When  the  fat  reaches  the  intestines,  part  of  it  is  free  and  a 
part  is  imprisoned  in  the  casein  clots  and  is  freed  from  them 
by  the  action  of  trypsin.  A  small  portion  of  the  fat  is  split 
up  into  fatty  acids  and  glycerin;  the  fatty  acids  combine  with 


DIGESTION.  83 

the  alkalies  of  the  digestive  juices  to  form  soaps.  This  saponi- 
fication, which  is  only  feeble,  has  long  been  attributed  to  steap- 
sin,  but  seems  really  to  be  due  to  the  action  of  microbes.  The 
sole  function  of  the  steapsin  is  to  emulsify  fats ;  emulsification 
is  favored  by  the  natural  viscosity  and  alkalinity  of  the  pan- 
creatic juices,  also  by  the  presence  of  soaps  and  free  fatty 
acids.  The  fat  which  is  emulsified  in  very  fine  droplets  is 
absorbed  directly  by  the  lacteals  of  the  villi;  the  remainder 
traverses  the  intestine,  undergoing  natural  saponification  and 
microbic  fermentation.  In  a  healthy  infant  fed  on  mother's 
milk,  rapidity  is  the  distinguishing  trait  of  intestinal  diges- 
tion. After  the  passage  of  the  chyme  into  the  duodenum,  its 
digestion  is  almost  complete.  Absorption  takes  place  actively 
in  the  upper  part  of  the  small  intestines,  especially  of  the 
albuminoids,  so  that  normally  we  find  few  traces  of  the  latter 
in  the  lower  part  of  the  intestinal  tract. 

Senator  considers  that  this  rapid  digestion  and  absorption 
explains  the  slight  degree  of  intestinal  putrefaction  when  the 
child  is  fed  on  breast-milk.  We  also  know  that  the  duodenum 
contains  the  fewest  microbes ;  lower  down,  where  they  are  more 
numerous,  they  do  not  find  putrescible  albuminoids  to  act  upon. 
After  the  absorption  of  the  food-stuffs  the  chyle  consists  prin- 
cipally of  the  following  substances:  biliary  residues,  whose 
destiny  we  know;  amido-acids,  various  acids  due  to  microbic 
fermentation;  soaps, — products  which  are  partly  absorbed  by 
the  portal  vein  and  transformed  by  the  liver  (thus  leucin  and 
tyrosin  are  changed  into  urea)  and  partly  eliminated  by  the 
faeces;  and  a  small  quantity  of  neutral  fats  and  acids  which 
are  passed  with  the  stools. 

With  all  this  there  still  remain  portions  of  the  food  sub- 
stance not  digested,  which,  with  the  other  residues,  are  the 
prey  of  microbes  and  give  rise  to  products  of  putrefaction, 
indol,  skatol,  phenol,  ammoniac,  and  various  toxins,  which 
are  also  partially  absorbed  and  transformed  by  the  liver  and 
partly  eliminated  by  the  faeces.     The  phenomena  of  putre- 


84  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

faction  attain  their  maximum  in  the  large  intestine,  but  nor- 
mally they  are  never  very  considerable:  witness  the  small 
amount  of  gas  in  the  colon  and  the  absence  of  fecal  odor  in 
the  stools. 

Summary. 

Casein  is  only  partially  digested  in  the  stomach,  especially 
when  cow's  milk  is  the  child's  food.  Pancreatic  digestion  plays 
the  chief  role  in  finally  converting  the  casein  into  a  form  in 
which  it  can  be  absorbed  by  the  duodenum  and  jejunum. 
Owing  to  the  small  amount  of  the  gastric  and  the  pancreatic 
secretions,  the  digestion  of  the  proteids  of  milk  (especially  of 
cow's  milk)  is  often  imperfectly  carried  out  during  the  first 
months  of  life.  In  the  healthy  breast-fed  child  the  proteid 
residue  is  small  and  intestinal  putrefaction  is  not  a  marked 
feature  of  digestion.  The  power  to  split  up  neutral  fats  is 
feeble  during  the  first  months  of  life;  so  also  is  the  power 
to  digest  starch.  Normally,  a  considerable  portion  of  the  fat 
is  excreted  in  the  stools.  Milk-sugar  is  readily  digested  by  the 
infant  and  normally  leaves  little  residue.  It  seems  probable, 
in  the  light  of  recent  investigations,  that  the  enzymes  which 
have  been  found  in  the  intestinal  secretions  and  in  mother's 
milk  play  a  not  inconsiderable  role  in  the  infant's  digestive 
processes. 

Experiments  in  Artificial  Digestion. 

The  following  conclusions  were  reached  by  J.  H.  Coriat  206 
and  A.  S.  Warthin  152  after  a  series  of  experiments  with 
rennin : 

1.  Casein  can  be  digested  by  both  pepsin  and  pancreatin 
without  being  first  coagulated  by  rennet.  2.  When  rennin  is 
also  present  the  amount  of  digested  proteid  or  albumose  proteid 
produced  by  the  proteolytic  enzymes  is  greater  in  every  case. 
3.  The  presence  of  rennin  is  necessary  to  secure  a  more  rapid 
and  energetic  casein  digestion.  4.  The  increased  peptone  pro- 
duction due  to  the  presence  of  rennin  takes  place  in  both 
acid   (pepsin)   and  alkaline   (trypsin)   media.     5.  Only  when 


DIGESTION.  85 

combined  hydrochloric  acid  exceeds  one-tenth  of  the  bulk  of 
the  milk  used  will  it  coagulate  milk,  but  not  as  rapidly  as 
free  hydrochloric  acid.  6.  Rennin  coagulates  milk  without 
hydrochloric  acid;  but  when  the  latter  is  present  in  combined 
form,  and  equal  to  one-tenth  or  less  of  the  bulk  of  the  milk 
used,  coagulation  takes  place  in  a  much  shorter  period  of  time. 
7.  The  presence  of  acid-albumin  hastens  coagulation  by  the 
enzymes.  8.  The  time  of  coagulation  decreases  steadily  as 
greater  amounts  of  absolute  rennin  are  present.  9.  Vegetable 
enzymes  coagulate  milk  in  a  way  which  compares  favorably 
with  rennin,  and  coagulation  takes  place  under  the  same  con- 
ditions as  to  temperature,  acidity,  and  quantity  present  as 
rennin.  10.  Enzymes  exist  in  the  plant  kingdom  which  have 
an  action  analogous  to  that  of  rennin. 

Rennet. 
Richmond.121  Rennet  acts  on  casein  only  in  neutral  or  acid 
solution.  The  optimum  temperature  is  41°  C.  (105°  F.),  the 
curd  being  firm.  At  a  low  temperature  (15°  to  20°  C.)  the 
curd  is  quite  soft  and  flocculent,  and  at  50°  C.  the  curd  be- 
comes very  soft.  The  larger  the  amount  of  acid  present  the 
greater  is  the  rapidity  of  its  action  on  milk.  The  addition  of 
water  to  milk  causes  it  to  be  acted  upon  more  slowly  by  rennet 
and  the  curd  is  less  firm.  By  heating  milk  the  action  of  rennet 
is  delayed,  owing  to  the  removal  of  some  of  the  soluble  calcium 
compounds.  By  adding  soluble  lime  salts  the  milk  will  be 
curdled  in  the  usual  manner. 

Excretion. 
Defecation.105 — In  the  new-born  and  in  the  infant  the  mus- 
cular wall  of  the  intestine  is  poorly  developed  and  peristaltic 
movements  are  feeble.  Zweifel  has  remarked  that  in  the  foetus 
the  intestinal  contents  move  with  extreme  slowness ;  in  a  foetus 
of  three  months  the  ileum  and  colon  are  empty;  it  is  only  at 
the  end  of  the  fourth  month  that  the  caecum  contains  meco- 


86  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

nium;   the  colon  does  not  contain  meconium  before  the  fifth 
month. 

After  birth,  when  food  is  introduced  and  the  secretion  of 
the  digestive  juices  becomes  established,  peristalsis  becomes 
more  active ;  the  progress  of  food  through  the  intestinal  tract, 
however,  is  due  perhaps  more  to  a  certain  vis  a  tergo  than  to  the 
influence  of  the  still  feeble  peristaltic  movements.  It  has  been 
calculated  that  the  chyle  takes  six  hours  to  traverse  the  intes- 
tinal tract. 

A  healthy  child  usually  has  three  or  four  evacuations  daily 
during  the  first  month  of  life,  two  or  three  a  day  for  the  next 
five  or  six  months,  and  one  or  two  a  day  during  the  remainder 
of  the  first  year  and  the  second  year.  Divers  causes  contribute 
to  bring  about  this  frequency  in  the  evacuations.  The  prin- 
cipal factors  are  the  large  number  of  meals,  the  relative  abun- 
dance of  food,  and  the  resulting  relatively  more  considerable 
proportion  of  fecal  material.  Other  factors  are  the  semi-liquid 
state  of  the  fasces  and  the  feebleness  of  the  anal  sphincter. 
We  must  not  forget  that  while  the  muscular  coat  of  the  intes- 
tine is  little  developed  at  birth,  its  reflex  excitability  is  greater 
in  the  new-born  and  in  the  infant,  since  the  still  imperfectly 
developed  cerebrum  does  not  restrain  the  functions  of  the  cord, 
whose  evolution  is  more  advanced. 

The  meconium  may  be  brown,  green,  or  black  in  color.  It 
consists  principally  of  epithelial  cells  from  the  intestinal  mu- 
cosa, mucus  and  biliary  secretions  and  pigments,  chlorides  and 
alkaline  sulphates,  a  very  small  amount  of  phosphates  and  a 
minimal  amount  of  iron  (Guillemonat),  leucocytes,  eholes- 
terin  and  hsematoidin  crystals,  and  grayish  and  fatty  granula- 
tions (debris),  probably  from  the  amniotic  fluid  swallowed. 
There  is  none  of  the  habitual  products  of  putrefaction  until  post- 
natal infection  has  occurred.  Meconium  is  usually  evacuated 
within  from  six  to  twelve  hours  after  birth,  and  is  absent  after 
the  first  two  or  three  days.  The  total  amount  averages  seventy- 
two  grammes  (Depaul). 


DIGESTION.  87 

The  amount  of  faeces  excreted  by  the  infant  is  greater  in 
proportion  to  the  body  weight  than  in  the  adult,  on  account 
of  the  relatively  greater  amount  of  nourishment  which  the 
former  takes.  According  to  Uffelmann,  an  infant  at  the  breast 
excretes  daily  three  grammes  for  each  kilogramme  of  body 
weight, — about  three  per  cent,  of  the  nourishment  taken; 
whereas  the  infant  fed  on  cow's  milk  excretes  from  four  to 
five  per  cent,  daily  (Monti). 

Michel 105  found  that  an  infant  at  the  breast  less  than  one 
month  of  age,  and  taking  half  a  litre  of  milk  a  day,  expelled 
daily,  on  the  average,  fifteen  grammes  of  liquid  faeces  or  three 
grammes  of  dried  faeces.  In  the  succeeding  months  this  can 
rise  to  eighty  grammes.  The  adult  passes,  on  the  average, 
one  hundred  and  seventy  grammes  daily. 

Towards  the  end  of  the  first  week  the  stools  of  the  healthy 
breast-fed  infant  become  of  normal  golden  color;  up  to  that 
time  they  have  a  greenish  tinge.  Even  under  normal  condi- 
tions the  faeces  of  healthy  children  contain  at  times  yellowish- 
white  masses.  These  do  not  consist  of  casein,  as  used  to  be 
thought,  but  are  mainly  made  up  of  fat.  Their  consistence  is 
that  of  a  soft,  semi-liquid  paste,  which,  while  it  is  favorable 
for  absorption,  also  renders  autointoxication  more  easy.  The 
odor  of  the  stools  is  not  distinctly  fecal,  but  resembles  that  of 
sour  milk,  and  is  not  especially  offensive.  In  healthy  breast-fed 
infants  the  reaction  of  the  stools  is  feebly  acid,  due  to  the 
presence  of  lactic  and  acetic,  perhaps  also  butyric  and  valeric 
acids,  which  come  from  the  fermentation  of  lactose.  These 
acids  must  exist  in  considerable  amount,  since  they  are  capable 
of  neutralizing  the  alkalinity  of  the  normal  intestinal  secre- 
tions. It  has  been  suggested  that  they  prevent  the  putrefaction 
of  albuminoid  substances. 

In  the  new-born  infant  the  pigment  of  the  faeces  consists 
principally  of  bilirubin.  Wegscheider  has  found  traces  of 
urobilin  (hydro-bilirubin),  though  Zweifel  and  Hoppe-Seyler 
deny   its   presence.     Wegscheider   found   at   times   biliverdin 


88  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

(Monti).  Blauberg  13  also  found  both  urobilin  and  biliverdin. 
He  states  that  the  stools  may  acquire  a  green  color  (due  to  bili- 
verdin) after  exposure  to  the  air  for  some  time.  On  the  other 
hand,  Pfeiffer  rejects  ZweifeFs  view  that  increased  acid  for- 
mation or  the  atmospheric  oxygen  gives  rise  to  this  greenish 
color,  and  considers  that  alkalinity  which  is  furthered  by  bac- 
terial development  is  responsible  for  it.  Hayem  and  others 
have  found  bacilli  which  produce  a  green  color.  Blauberg 
thinks  that  not  improbably  ferments  share  in  producing  it.* 

Marfan.105  Infants'  stools  contain  from  eighty  to  eighty-five 
per  cent,  of  water  (Blauberg  gives  from  seventy-five  to  eighty- 
five  per  cent.).  The  dry  residue  consists  of  food  remnants, 
intestinal  secretions,  and  bacteria.  Faint  traces  of  peptone  are 
present  (Blauberg,  Wegscheider,  Uffelmann). 

Uffelmann  has  maintained,  in  opposition  to  Wegscheider, 
that  at  times  leucin  and  tyrosin  are  found.  The  absence  of 
products  of  putrefaction  in  normal  digestion  helps  to  explain 
the  feeble  toxicity  of  the  faeces  (Bouchard) .  Indol  is  ordinarily 
absent,  but  it  may  be  present,  as  well  as  skatol  and  phenol 
(Uffelmann,  Blauberg).  Oxyacids  are  always  present  (Winter- 
nitz,  Blauberg).  Blauberg  finds  that  small  amounts  of  lactose 
are  present  during  the  first  week  of  life.  Marfan,  on  the  other 
hand,  states  that  there  are  no  traces  of  sugar  in  the  faeces,  but 
merely  the  products  of  fermentation  of  lactose,  especially  lactic, 
acetic,  butyric,  and  valeric  acids.  The  presence  of  acetic  acid 
seems  highly  probable  (Blauberg),  since  Baginsky  has  demon- 
strated that  lactose  is  decomposed  in  the  intestine  into  acetic 

*  The  analyses  of  faeces  published  by  Wegscheider  in  1875,  in  his 
treatise  "  On  the  Normal  Digestion  of  the  Infant,"  were  as  follows : 
one  hundred  parts  of  faeces  contain:  water,  83.13  per  cent.,  organic 
matter  13.71  per  cent.,  salts  1.16  per  cent.  Ten  analyses  of  the  solids 
gave  3.39  per  cent,  for  mucin,  epithelial  debris,  and  lime  salts,  aque- 
ous extractives  5.35  per  cent.,  alcoholic  extracts  0.82  per  cent.,  choles- 
terin  0.32  per  cent.,  mineral  salts  1.36  per  cent.,  fat  and  fatty  acids 
1.44  per  cent. 


DIGESTION  89 

and  carbonic  acids,  methane,  and  water.  The  small  amount  of 
gas  in  the  intestines  is  almost  odorless,  or  smells  weakly  of 
butyric  acid.  It  consists  of  carbon  dioxide,  nitrogen,  hydrogen, 
and  methane. 

Fat  constitutes  the  major  part  of  the  infant's  faeces.  It  is 
present  as  globules  of  neutral  fat,  crystals  of  the  fatty  acids, 
and  especially  lime  soaps  (oleate,  palmitate,  and  stearate  of 
lime).  The  amount  of  fat  in  the  dried  stools  varies  much, 
according  to  different  investigators.  Wegscheider  placed  it 
at  from  nine  to  twelve  per  cent.,  Biedert  at  ten  to  twenty  per 
cent.,  Bendix  at  fourteen  to  twenty  per  cent.,  while  Heubner 
considers  twenty-five  per  cent,  the  maximum.  Tschernow 
gives  twenty  to  thirty  per  cent,  and  Michel  twenty  per  cent, 
as  the  average.  The  large  amount  of  fat  not  assimilated  is 
remarkable.  It  would  certainly  seem  as  if  the  presence  of  an 
excess  of  fat,  of  which  only  a  part  is  absorbed,  is  essential 
for  the  normal  digestion  of  mother's  milk. 

Blauberg  found  for  the  first  week  of  life  that  the  mineral 
substances  amounted  to  thirteen  and  a  half  per  cent,  of  the 
dried  faeces.  About  half  of  these  are  soluble  in  dilute  hydro- 
chloric acid. 

The  lime  salts  amount,  on  the  average,  to  15.31  per  cent, 
of  the  soluble  ash.  The  phosphoric  acid  varies  from  ten  to 
thirteen  and  a  half  per  cent.  Considerable  amounts  of  lime 
are  in  combination  with  organic  acids. 

According  to  Uffelmann,  from  twenty-nine  to  thirty-one  per 
cent,  of  the  fecal  ash  and  ten  per  cent,  of  the  dried  residue 
consist  of  lime,  besides  which  potash,  soda,  chlorine,  and  sul- 
phuric and  phosphoric  acids  are  present.  A  portion  of  these 
minerals  was  originally  present  as  carbonates  and  soaps. 

Uffelmann  161  investigated  the  faeces  of  nine  children,  all  at 
the  breast  and  getting  no  other  food,  varying  in  age  from  one 
week  to  one  year.  He  found  a  small  amount  of  albuminoids, 
fat,  free  fatty  acids,  soaps  (especially  earthy  soaps),  potash, 
soda,  lime,  magnesia,  and  iron  salts,  united  to  hydrochloric, 


90  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

sulphuric,  and  phosphoric  acids,  and  organic  acids,  besides 
mucus,  epithelia,  cocci  and  bacilli,  hay  bacilli,  biliary  coloring 
matter  (altered  and  unaltered),  cholalic  acid,  cholesterin,  and 
at  times  leucin  and  tyrosin.  The  water  content  was  much  more 
considerable  than  that  of  adult  fasces ;  next  to  water,  the  chief 
constituents,  reckoned  according  to  their  weight,  were  the 
masses  of  bacteria,  mucus,  and  epithelium,  next  the  fat  and 
fatty  acids,  and  finally  the  salts.  Of  fifteen  parts  of  solids 
in  one  hundred  parts  of  faeces,  one  and  a  half  are  inorganic, 
thirteen  and  a  half  organic;  of  the  latter,  fat  and  fatty  acids 
constitute  from  two  to  three  parts,  there  are  traces  of  proteids 
up  to  0.2  part  and  cholesterin  up  to  0.2  part;  of  the  remnant, 
from  eight  to  eight  and  a  half  parts  consist  of  bacteria,  mucus, 
and  epithelial  cells.  The  faeces  never  show  a  uniform  propor- 
tion in  their  different  ingredients. 

Blauberg  13  found  cholesterin  always  present,  also  lecithin, 
but  only  in  minute  amounts.  Paul  Muller  194  also  found  a 
small  amount  of  lecithin  uniformly  present.  Bile  acids  are 
present  in  small  quantities;  Jacubowitsch  denies  that  glyco- 
cholic  acid  is  present,  but  Baginsky  states  that  he  has  found  it. 

Blauberg' s  tests  for  nucleins  in  the  fasces  of  breast-fed  infants 
resulted  negatively,  but  he  was  able  to  demonstrate  them  in 
the  faeces  of  artificially  fed  children.  While  Knopfelmacher 
could  detect  no  albumin  remnant  in  the  faeces  of  breast-fed 
infants,  Blauberg  finds  that,  as  a  rule,  albumin  is  present  in 
minute  amounts  during  the  first  week  of  life.  These  may  be- 
come considerable  if  there  are  digestive  disturbances. 

Biliary  residues  are  abundant;  the  following  ferments  have 
been  discovered:  a  saccharifying  ferment  (Wegscheider, 
Moro),  an  inverting  ferment  (Jacks,  Miura),  and  a  pepto- 
nizing ferment  (Baginsky). 

There  are  normally  present  a  small  amount  of  mucus  and 
hosts  of  bacteria. 

Marfan.105  The  faeces  of  an  infant  fed  on  cow's  milk  (even 
if  it  is  sterilized,  and  especially  if  the  milk  is  given  undiluted) 


DIGESTION.  91 

are  noticeably  different  from  the  evacuations  of  the  nursing 
infant.  They  are  firm,  pasty,  somewhat  dry,  and  of  a  pale 
yellow  color  with  a  feebly  ammoniacal  odor.  After  evacuation 
their  color  at  times  turns  gray  (Uffelmann),  whereas  the  stools 
of  breast-fed  infants  are  apt  to  assume  a  greenish  hue.  The 
reaction  of  the  stools  is  generally  alkaline  or  neutral ;  at  times 
it  is  feebly  acid.  The  alkalinity  results  either  from  ammoniacal 
fermentation  or  from  the  excess  of  mucus  which  is  apt  to  be 
present  owing  to  a  slight  degree  of  catarrh.  Blauberg  found 
lactic  acid,  fatty  acids,  and  iron  in  decidedly  larger  quantities 
in  the  faeces  of  the  breast-fed  than  of  the  bottle-fed  infant. 
Indol  is  more  frequently  present  in  the  evacuations  of  artifi- 
cially fed  infants  (Uffelmann). 

To  conclude,  the  faeces  of  an  infant  fed  on  cow's  milk  con- 
tain more  proteids  (nucleins),  fat,  lime  salts,  and  phosphoric 
acid,  and  less  iron,  and  they  are  more  copious  relatively  to  the 
amount  of  food  ingested  than  is  the  case  in  breast-fed  infants.* 

Biedert.7  Under  the  microscope  casein  appears  as  finely 
granular  masses;  the  fat-droplets  resemble  mother-of-pearl, 
and  are  scattered  through  the  faeces  in  moderate  quantity. 
These  run  together  into  larger  drops  in  the  evacuations  of 
young  breast-fed  infants  and  when  there  are  digestive  dis- 
turbances. We  also  find  fatty  acid  crystals  and  salts  of  the 
fatty  acids  which  are  either  star-shaped  or  arranged  in  clus- 
ters, or  form  glistening  yellowish  amorphous  clumps.  Mucus 
appears  as  hyaline  delicately  folded  bands,  which  run  through 
the  field,  often  with  round  cells  or  blood-cells  sticking  to  them. 
Many  bacteria  are  present. 

Biedert  gives  the  following  directions  for  the  examination 
of  faeces.    If  proteids  are  present  in  the  form  of  whitish  lumps, 

*  Knopf elmacher  87  in  1899  investigated  the  so-called  casein  flakes  in 
the  faeces  of  dyspeptic  infants  fed  on  cow's  milk,  and  found  that  they 
contained  from  2.988  to  3.53  per  cent,  nitrogenous  material,  twenty- 
five  to  forty  per  cent,  fat,  and  18.08  per  cent,  ash  (the  faeces  were  dried 
on  the  water-bath,  hence  not  free  from  water). 


92  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

the  specimen  should  be  diluted  with  distilled  water  in  a  test- 
tube,  after  which  Millon's  reagent  should  be  added.  If  the 
masses  consist  chiefly  of  proteids,  they  will  form  reddish  lumps ; 
if  they  are  mingled  with  any  considerable  quantity  of  soaps 
or  salts,  the  latter  will  become  soluble  and  the  solid  masses 
or  lumps  will  disintegrate.  If  the  fluid  is  heated,  an  excess 
of  fat  can  be  recognized  by  the  presence  of  fat-globules.  Under 
the  microscope  these  white  lumps  are  recognized  by  their  finely 
granular  consistence;  they  are  structurally  similar  to  milk- 
clots,  and  enclose  fat-droplets  within  the  finely  granular  casein. 
Fine  waxy  threads  of  mucin  enclosing  mucus  cells  in  their 
meshes  are  to  be  seen,  and  must  be  differentiated  from  the 
above. 

Absorption. 

Marfan.105  The  amount  of  food  absorbed  and  assimilated 
by  the  infant  fed  on  cow's  milk  is  estimated  at  ninety-three 
per  cent,  instead  of  ninety-six  per  cent,  for  the  breast-fed 
infant.  The  percentage  of  casein  absorbed  by  the  breast-fed 
infant  is  given  by  Michel  as  from  ninety-four  to  ninety-nine 
per  cent.  According  to  the  researches  of  Eaudnitz,  Lange, 
Bendix,  Grosz,  Lange  and  Berend,  Knopfelmacher,  Keller,  and 
Michel,  the  proportion  of  nitrogenous  matter  absorbed  by  the 
intestine  in  infants  fed  on  cow's  milk  is  very  variable,  but 
generally  less  than  that  found  in  nursing  babies;  it  varies 
between  ninety-three  and  seventy  per  cent.  If  the  child  suffers 
from  digestive  disturbances,  the  amount  will  be  still  lower. 
Where  there  is  no  digestive  disturbance,  the  utilization  of  lac- 
tose will  be  about  the  same  in  the  breast-fed  and  the  artificially 
fed  infant;  but  the  absorption  of  mineral  salts,  especially  of 
lime  and  phosphoric  acid,  is  decidedly  less  complete  in  the 
bottle-fed  infant.  Biedert  emphasizes  the  importance  of  the 
form  of  emulsion  in  which  the  fat  exists:  the  finer  it  is  the 
better  will  it  be  absorbed.  The  proportion  of  fat  absorbed 
varies  from  ninety  to  ninety-eight  per  cent. ;  it  is  always  higher 
in  the  breast-fed  infant. 


DIGESTION.  93 

The  Stools  in  Pathological  Conditions. 
Abnormal  types  of  stools  may  be  classified,  according  to 
Chapin,201  as  follows: 

I.  Green  Stools. — Stools  can  only  be  considered  green  when 
that  condition  is  evident  immediately  npon  their  passage. 
The  color  is  due  to  fermentation,  which  doubtless  results  from 
bacterial  action.  All  stools  become  green  a  certain  time  after 
passage,  causes  by  oxidation  of  the  air. 

II.  Curdy  Stools. — Curdy  lumps  may  be  produced  by  un- 
digested casein  or  fat.  The  former  are  hard  and  yellowish, 
while  the  latter  are  soft  and  smooth  like  butter. 

III.  Slimy  Stools. — These  are  the  result  of  catarrhal  in- 
flammation. When  the  mucus  is  mixed  with  fecal  matter,  the 
irritation  is  high  up  in  the  bowel;  but  when  flakes  or  masses 
of  mucus  are  passed,  the  trouble  is  near  the  outlet. 

IV.  Yellow,  Watery  Stools. — These  are  seen  in  depressed 
nervous  conditions,  especially  in  the  hot  days  of  summer,  when 
the  bowel  is  relaxed  and  the  inhibitory  fibres  of  the  splanchnic 
nerves  do  not  act  to  advantage. 

V.  Very  Foul  Stools. — These  are  caused  by  decomposition 
of  the  albuminoid  principles  of  the  food. 

VI.  Profuse,  Colorless,  Watery  Stools,  with  Little  Fecal 
Matter. — These  are  doubtless  caused  by  an  infective  germ  akin 
to  that  of  Asiatic  cholera.  This  condition  is  known  as  cholera 
infantum. 

These  types  are  rarely  seen  alone,  but  are  frequently  found 
in  all  sorts  of  combinations  (except  the  last). 


CHAPTBE    V. 
MODERN  METHODS   OF  INFANT  FEEDING. 

The  views  of  the  leading  pediatrists  of  Germany,  France, 
England,  and  the  United  States  differ  more  or  less  widely  on 
the  subject  of  infant  feeding,  yet  certain  general  principles 
may  be  evolved  from  their  teachings.  Short  abstracts  of  the 
views  of  Biedert,  Monti,  Baginsky,  Holt,  Rotch,  and  other 
prominent  teachers  abroad  and  in  this  country  have  been  pre- 
pared that  the  reader  may  learn  how  great  a  variety  of  methods 
have  been  advocated  for  the  artificial  feeding  of  infants. 

Biedert  7  advises  that  cow's  milk  should  be  diluted  three 
or  four  times  when  it  is  to  be  given  to  a  very  young  infant 
or  one  with  a  weak  digestion ;  after  the  first  two  to  three  weeks 
dilute  with  twice  the  quantity  of  water;  from  two  to  three 
months  increase  gradually  to  equal  parts;  from  four  to  six 
months  give  two  parts  of  milk  to  one  part  of  water,  then  three 
parts  of  milk  to  one  of  water,  four  to  one,  and  from  the  eighth 
to  the  twelfth  month  pure  milk.  The  change  in  strength  of 
the  addition  should  be  made  when  the  child  ceases  to  gain  in 
weight,  provided  the  digestion  is  perfect.  He  advises  the  use 
of  pure  grape-sugar  or  lactose,  to  make  a  proportion  of  six 
per  cent,  in  the  diluted  milk.  Cane-sugar  or  beet-sugar  may 
be  used  instead;  the  latter  is  cheaper.  Lactose,  on  the  whole, 
seems  preferable;  it  is  the  natural  sugar  present  in  milk,  and 
also  has  the  property  of  aiding  in  the  digestion  of  proteids. 
By  splitting  up  into  lactic  acid  it  acts  as  an  intestinal  anti- 
septic. 

Wheat-,  barley-,  or  oatmeal-water,  or  plain  water,  may  be 
used  as  diluents,  according  to  the  state  of  the  child's  diges- 
tion. 

94 


MODERN   METHODS   OF   INFANT   FEEDING.  95 

Biedert  estimates  that  from  one  hundred  and  fifty  to  two 
hundred  cubic  centimetres  of  food  are  necessary  for  each  kilo- 
gramme of  body  weight  during  the  twenty-four  hours.  Feed 
at  first  every  two  hours;  then  rapidly  diminish  the  number 
of  feedings  to  eight,  seven,  six,  or  even  five  in  the  twenty-four 
hours;  avoid  night  feedings  if  possible.  When  a  child  is 
weakly,  it  can  be  fed  every  two  and  a  half  or  three  hours 
from  four  a.m.  to  ten  p.m., — that  is,  seven  or  eight  meals  a 
day. 

Biederfs  Cream  Mixture. 


Casein . 

Fat. 

Sugar. 

Calories 

Age. 

Cream. 

Water. 

Sugar. 

Milk. 

Per 

Per 

Per 

in  100 

Litre. 

Litre. 

Grammes. 

Litre. 

cent. 

cent. 

cent. 

cc. 

First  month 

•      * 

3 

18 

0.9 

2.5 

5 

47 

Second  month 

•      I 

3 

8 

18 

l 
T<5 

1.2 

2.6 

5 

49 

Third  to  fourth  month . 

•      £ 

3 

8 

18 

i 

1.4 

2.7 

5 

51 

Fourth  to  fifth  month  . 

•      1 

3 

8 

18 

I 

1.7 

2.9 

5 

54 

Sixth  to  seventh  month 

•      i 

3 

8 

18 

3 
8 

2.0 

3.0 

5 

56 

Eighth  to  twelfth  month 

•      i 

J 

12 

i 

2.5 

2.7 

5 

56 

A  cream  containing  from  eight  to  ten  per  cent,  fat  should 
be  used  in  this  mixture.  In  his  latest  edition  Biedert  recom- 
mends six  per  cent,  sugar  instead  of  five  per  cent.  Indi- 
cations for  using  the  cream  mixture  are  given  by  Biedert  as 
follows:  prolonged  digestive  disturbances  which  do  not  yield 
to  simple  dilution  of  cow's  milk,  constipation  alone  or  alter- 
nating with  enteritis,  and  mucous  enteritis.  A  bad  result 
means,  of  course,  that  the  digestive  apparatus  cannot  handle 
fat.  If  fat  diarrhoea  occurs,  we  may  have  to  used  skimmed 
milk. 

Biederfs  Cream  Conserve  is  a  paste  containing  7.1  per  cent, 
casein,  15.5  per  cent,  fat,  and  thirty-five  per  cent,  sugar,  ster- 
ilized by  heat.  A  large  number  of  formulae  can  be  constructed 
by  the  addition  of  milk  and  water  to  this  conserve.  For  ex- 
ample : 


96  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

Mixture  No.  1. 


One  tablespoonful  conserve. . . 
Thirteen  tablespoonfuls  water. 
Two  tablespoonfuls  milk 


Mixture  No.  5. 


One  tablespoonful  conserve.  . . 
Thirteen  tablespoonfuls  water. 
Six  tablespoonfuls  milk 


~\        i  1.0  per  cent,  albumin 

1.7  per  cent.  fat. 

8.8  per  cent,  sugar. 


1.5  per  cent,  albumin. 


"A  C  1.5  per  cent,  alb 
r  =  4  2. 1  per  cent,  fat 
J        v  8.5  ner  cent,  sus 


3.5  per  cent,  sugar. 


Many  of  the  other  thickened  cream  conserves,  such  as  Lah- 
niann's  Vegetable  Milk,  Loeflund's  Cream  Conserve,  and  Allen- 
bury's  Infant  Foods,  are  compounded  on  similar  lines. 

At  the  1899  meeting  of  the  Society  of  German  Naturalists 
and  Physicians  Biedert  stated  that  we  should  not  use  one 
type  of  milk  for  all  cases,  but  a  mixture  of  milk,  cream,  water, 
or  other  diluents  which  can  be  altered  at  will. 

Heubner  70  thinks  that  healthy  children  can  be  given  large 
amounts  of  proteids  without  harm;  an  excess  of  proteids  is 
less  harmful  than  an  excess  of  fluids.  Basch  has  shown  that 
casein  is  well  digested  by  trypsin  in  the  space  of  from  four 
to  five  hours  without  leaving  any  nuclein  remnant.  The 
presence  of  undigested  casein  in  the  diarrhceal  stools  does  not 
prove  that  the  healthy  infant  cannot  digest  casein  in  proper 
amount. 

Heubner's  method,  which  can  also  be  called  the  calorimetric, 
is  based  on  the  principle  of  diluting  cow's  milk  as  little  as 
possible;  it  is  intended  to  furnish  a  food  mixture  which  will 
closely  resemble  mother's  milk  in  the  number  of  calories  it 
contains. 

Heubner's  Mixture  is  prepared  as  follows :  one  pint  of  cow's 
milk  is  diluted  with  half  a  pint  of  oatmeal-  or  barley-water, 
sterilized  in  the  Soxhlet  apparatus  for  fifteen  minutes,  and 
quickly  cooled  and  kept  cool  till  ready  for  use.  Instead  of 
the  oatmeal-water,  two  teaspoonfuls  of  Bademann's  or  Kufeke's 
Meal  may  be  added  to  a  pint  of  water  and  boiled  down  to 


MODERN   METHODS   OF   INFANT   FEEDING.  97 

half  a  pint  (from  a  half  to  three-quarters  of  an  hour) .  Enough 
lactose  should  be  added  to  the  mixture  to  make  the  percentage 
of  sugar  equal  seven;  this  should  be  done  in  the  last  five 
minutes. 

One  litre  of  this  mixture  will  represent  two  per  cent,  pro- 
teids,  2.2  per  cent,  fat,  and  7.2  per  cent,  sugar,  and  will  be 
equivalent  to  five  hundred  and  eighty  calories.  This  mixture 
is  not  suited  to  every  case;  for  children  of  very  low  weight, 
with  weak  digestive  powers,  and  for  sick  infants  we  must  use 
sometimes  a  weaker  mixture, — namely,  we  must  dilute  the 
milk  one-half  or  two-thirds.  The  child  should  be  fed  every 
three  hours. 

Feer  53  gives  in  the  subjoined  table  the  amounts  of  cow's 
milk,  water,  and  lactose  administered  in  the  Heubner-Hoff- 
mann-Soxhlet  Mixture  at  different  periods  of  the  infant's  life, 
and  compares  the  figures  with  the  quantities  required  by  the 
child  at  the  breast.  They  represent  the  total  quantity  in  the 
twenty-four  hours. 

Breast-milk.     Cow's  milk.    Water.      Lactose. 
Cc.  Cc.  Cc.       Grammes. 

First  week 300  50-200  100  12 

Second  week 550  350  200  24 

Third  week 600  400  200  .24 

Fourth  week 650  400  250  30 

Fifth  week 700  450  250  30 

Sixth  week 750  500  250  30 

Seventh  to  eighth  week 800  520  300  37 

Ninth  to  twelfth  week 825  550  300  37 

Thirteenth  to  sixteenth  week  875  600  300  37 

Seventeenth  to  twentieth  week 925  600  350  43 

Twenty-first  to  twenty-fourth  week . .  975  650  350  43 

Heubner.70  In  the  nourishment  of  the  breast-fed  infant  the 
quantitative  are  greater  than  the  qualitative  differences;  this 
without  prejudice  to  the  growth  of  the  child.     The  number 

7 


98 


THE   ARTIFICIAL   FEEDING   OF   INFANTS. 


of  calories  required  by  children  of  equal  weight  and  develop- 
ment varies  greatly.  This  has  been  shown  by  a  series  of  obser- 
vations on  the  children  of  physicians.  Children  of  equalv weight 
and  age  would  take  quantities  varying  widely,  some  requiring 
twice  as  much  as  others.  Qualitative  tests  of  the  milk  were 
not  carried  out,  but  it  is  not  likely  that  they  varied  sufficiently 
to  account  for  such  differences.  The  mothers  all  lived  under 
good  hygienic  conditions. 

Heubner  gives  the  following  table  of  the  number  of  calories 
consumed  by  children  on  different  milk  mixtures : 


A  child  weighing  3300  grammes  will  take 
A  child  weighing  4000  grammes  will  take 
A  child  weighing  4500  grammes  will  take 
A  child  weighing  5400  grammes  will  take 


Mother's 
milk. 

Calories. 

328 
409 
502 
496 


Heubner's 
Two-thirds 

Mixture. 

Calories. 

360 
450 
540 
540 


Biedert's 
One-third 
Mixture. 
Calories. 

214 

260 

318 

350 


Camerer  and  Soldner  find  very  low  fat  percentages  in 
mother's  milk  in  the  latter  months  of  lactation.  Between  the 
third  week  and  the  fourth  month  the  average  is  3.66  per  cent. 
We  can  assume  an  average  of  3.5  per  cent,  without  danger  of 
giving  too  high  a  figure.  In  one  litre  of  mother's  milk  there 
are  from  ten  to  twelve  grammes  of  proteids,  yielding  from 
forty-one  to  forty-nine  calories;  thirty-five  grammes  of  fat, 
yielding  325.5  calories;  and  sixty-five  grammes  of  sugar,  yield- 
ing 266.5  calories;  total,  six  hundred  and  twenty  calories. 

Children  of  equal  age  and  weight,  fed  on  greatly  different 
amounts  of  milk  (even  double  the  quantity,  vide  supra),  will 
show  a  like  increase  in  weight.  It  is  evident,  then,  that  differ- 
ent children  require  a  different  number  of  calories  per  kilo- 
gramme of  body  weight  for  their  growth  and  nourishment. 
If  this  difference  exists  in  human  milk,  we  should  expect  to 
find  that  the  same  holds  good  in  the  case  of  artificially  fed 
infants.     Some  will  thrive  on  low  proteids  and  high  fat  per- 


MODERN   METHODS   OF   INFANT   FEEDING.  99 

centages;  or,  vice  versa,  on  high  proteids  and  low  fat;  or  on 
a  mixture  rich  in  sugar,  such  as  condensed  milk  preparations; 
or  on  preparations  containing  starches;  or  even  on  peptone 
and  egg  albumin,  granting  the  necessary  cleanliness  in  the 
preservation  and  the  preparation.  These  kinds  of  foods  are 
useful  in  tiding  the  infant  over  to  a  diet  of  cow's  milk,  slightly 
diluted,  or  to  mixed  feeding.  They  do  not  all  possess  the  same 
food  value.  Some  make  more  demands  on  the  infant's  diges- 
tion than  do  others;  at  the  same  time,  infants  seem  to  be 
able  to  dispose  of  very  differently  constituted  food-stuffs.  We 
should  not  depend  on  the  infant's  powers  of  digestion,  but 
should  as  far  as  possible  take  the  child's  natural  food  (breast- 
milk)  as  an  example. 

Gaertner's  Milk  has  an  average  value  of  six  hundred  and 
twelve  calories  per  litre,  and  Backhaus  Milk  six  hundred  and 
thirty  calories  to  one  litre. 

Proteids.  Fat.  Sugar. 

Per  cent.  Per  cent.  Per  cent. 

Woman's  milk 1-1.2  3.5-4  6.5-7 

Backhaus  Milk 1.75  3.25  6.75 

Gaertner's  Milk 1.67  3.2  6.00 

Heubner's  Mixture  (two-thirds  strength).  2.27  2.3  7.00 

Heubner  is  inclined  to  think  that  scurvy  may  follow  the  pro- 
longed use  of  these  prepared  infant  foods.  While  sterilization 
may  also  carry  dangers  with  it  in  this  respect,  it  is  unfortu- 
nately necessary. 

The  value  of  the  artificial  cream  foods  is  at  present  estab- 
lished more  on  a  theoretical  than  a  practical  basis.  The  value 
of  any  child's  food  depends  largely  on  the  cleanliness  observed 
in  its  handling  and  preparation,  its  administration  in  correct 
quantities  (without  other  food),  and  the  general  hygiene  sur- 
rounding the  child's  person. 

Bendix  10  thinks  that  it  is  not  so  much  the  question  how 
to  render  the  casein  digestible  as  how  to  reduce  it  to  the  proper 


100  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

proportion  by  dilution  with  water  or  barley-water.  He  agrees 
with  Heubner  that  one  should  give  the  actual  amounts  of  the 
food  constituents  which  are  necessary  without  laying  too  much 
stress  on  the  relative  dilution. 

Seifert,59  in  the  last  edition  of  Gerhardt's  text-book,  advises 
that  the  Heubner-Hoffmann  Mixture  should  be  used,  sterilized 
in  the  Soxhlet  apparatus.  The  latter  is  not  perfect,  but  it  is 
at  present  the  best  means  we  have  for  rendering  the  milk  sterile 
and  so  adapted  to  the  infant's  use. 

Henoch,71  in  the  last  edition  of  his  "  Lectures  on  Children's 
Diseases/'  recommends  for  the  first  two  or  three  months  one 
part  of  milk  to  two  or  three  parts  of  water;  from  four  to  six 
months  one  part  of  milk  to  two  of  water;  from  six  to  nine 
months  equal  parts,  or  two  parts  of  milk  to  one  of  water ;  after 
ten  months  he  gives  whole  milk.  Each  case  should  be  fed 
according  to  its  particular  needs. 

Baginsky  6  finds  that  two  essential  difficulties  exist  in  the 
problem  of  infant  feeding :  first,  the  qualitative  and  quantita- 
tive differences  in  the  chemical  composition  of  woman's  milk 
and  cow's  milk;  second,  the  presence  of  bacteria  and  their 
toxins.  When  the  dirt  and  bacterial  content  of  cow's  milk  are 
diminished,  the  results  of  feeding  children  with  it  are  so  satis- 
factory that  in  the  case  of  healthy  infants  elaborate  methods 
of  altering  its  composition  become  of  little  value  or  even  super- 
fluous. With  regard  to  the  first  point,  we  must  reduce  the 
proteid  percentage  and  add  sugar.  The  numerous  quantitative 
variations  in  the  proteid  content  of  mother's  milk  prevent  the 
establishment  of  an  absolute  standard  for  the  degree  of  dilu- 
tion ;  neither  can  the  total  quantity  of  food  to  be  administered 
daily  be  rigidly  determined.  As  the  amount  of  milk  which 
a  child  at  the  breast  will  take  varies  within  considerable  limits 
in  each  individual  case,  so  also  in  the  case  of  cow's  milk  it 
is  impossible,  in  the  absence  of  a  more  definite  basis  for  com- 
putation, to  establish  any  absolutely  fixed  or  definite  standard 
for  the  total  quantity  to  be  given.    Biedert  has  calculated  that 


MODERN    METHODS   OF   INFANT   FEEDING.  101 

when  cow's  milk  is  diluted  so  that  its  casein  content  amounts 
to  one  per  cent.,  the  infant  requires  for  each  kilogramme  of 
his  body  weight  two  hundred  cubic  centimetres  of  milk.  This 
rule  may  hold  good  for  many  cases,  but  the  degree  of  dilution 
and  the  total  daily  quantity  of  food  must  be  determined  finally 
by  the  digestive  capacity  in  each  individual  case.  The  latter  is 
best  estimated  by  the  use  of  the  scales.  Some  children  certainly 
tolerate  more  concentrated  nourishment  and  more  liberal  quan- 
tities of  food  than  others.  In  fact,  many  authors,  especially 
the  French  (Budin,  Variot,  and  others),  advise  to  give  whole 
milk  from  the  beginning.  On  the  other  hand,  some  infants 
digest  casein  with  difficulty,  while  in  other  cases  richness  in 
fat  content  is  the  stumbling-block.  Only  the  most  careful 
observation  of  the  child's  general  condition  and  inspection  of 
the  faeces  will  save  the  physician  from  mistakes  in  treatment. 
In  general  one  can  begin  with  a  dilution  of  three  parts  of  water 
and  one  part  of  milk,  gradually  diminishing  the  amount  of 
water  until,  towards  the  end  of  the  third  month,  a  mixture 
of  equal  parts  of  milk  and  water  is  reached.  Instead  of  water, 
dilute  oatmeal-water  may  be  used,  or  solutions  of  one  of  the 
infant  foods.  The  addition  of  milk-sugar  must  not  be  for- 
gotten. Whole  milk  is  often  well  tolerated  at  the  end  of  the 
ninth  month.  In  view  of  what  has  been  said,  the  following 
table  of  quantities  at  each  feeding  is  to  be  considered  merely 
a  general  guide  for  the  practitioner;  it  is  not  intended  to 
take  the  place  of  careful  personal  observation  and  study  of 
the  needs  of  each  individual  case  (size,  weight,  power  of 
digestion,  etc.).  Baginsky  has  found  this  method  of  dilution 
satisfactory  in  a  practice  covering  many  years.  He  sees  no 
reason  to  modify  it  in  any  essential  respect,  notwithstanding  the 
fact  that  the  recent  metabolism  work  of  Heubner  and  Rubner 
seems  to  controvert  its  principles.  Each  child  has  its  individ- 
ual powers  of  digestion.  It  is  well  to  begin  with  the  more 
dilute  mixtures  and  to  advance  to  those  more  concentrated, 
guided  always  by  the  results  of  careful  clinical  observation. 


10f2 


THE   ARTIFICIAL   FEEDING   OF   INFANTS. 


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MODERN    METHODS   OF   INFANT   FEEDING.  103 

The  use  of  barley-water  and  similar  weak  starchy  prepara- 
tions has  long  been  recommended  and  is  of  undoubted  value 
in  rendering  milk  more  digestible  by  lessening  the  size  of  the 
clots.  Kudisch's  proposal  to  effect  the  same  by  the  addition 
of  dilute  hydrochloric  acid  has  not  found  favor.  Monti's  Whey 
Mixture,  Voltmer's  Mother's  Milk,  and  Backhaus  Milk  are 
defective  in  that  they  show  a  departure  from  the  normal, — 
a  deficiency  in  either  fat,  albumin,  or  sugar  which  is  hard  to 
remedy.  Doubtless  they  will  all  give  good  results  in  a  large 
number  of  cases,  but  as  certainly  not  in  all  cases,  and  faulty 
nutrition  will  result  unless  the  greatest  care  is  exercised.  It 
is  a  mistake  to  use  calories  as  a  basis  for  feeding  infants; 
reckonings  of  this  kind  are  of  value  in  estimating  the  total 
food  requirements  of  the  organism,  but  one  should  never,  on 
this  theoretical  basis,  attempt  to  substitute  fat  for  proteids 
or  sugar  for  fat. 

The  infant's  body  requires,  even  more  than  the  adult's,  a 
definite  quantity  of  food-stuffs  for  the  period  of  growth,  and 
it  will  more  easily  select  and  assimilate  the  same  from  a 
mixture  of  apparently  faulty  qualitative  composition  than 
it  will  handle  a  food  which  theoretically  and  quantitatively 
is  correctly  put  together  to  represent  a  certain  value  in  calo- 
ries. If  the  organism  needs  fat,  it  will  not  thrive  if  sugar 
is  offered  in  its  place;  the  same  is  true  of  albumin.  Herein 
lies  the  great  danger  of  the  modern  habit  of  considering  this 
question  from  the  chemical  stand-point. 

Baginsky  does  not  recommend  the  use  of  Rieth's  Albumose 
Milk,  Lahmann's  Vegetable  Milk,  Gaertner's  Fat  Milk,  or 
Loeflund's  Cream  Conserve.  All  conserves  are  distinctly  in- 
ferior to  fresh  cow's  milk,  and  their  use  is  apt  to  be  followed 
by  severe  anaemia  and  scurvy. 

Monti."  When  cow's  milk  is  to  be  used  as  an  infant  food, 
the  following  principles  must  be  kept  in  mind :  ( 1 )  The  acid- 
ity must  be  diminished,  as  it  is  three  times  that  of  mother's 


104  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

milk.*  (2)  The  casein  must  be  diminished  and  its  tendency 
to  clot  in  large  lumps  altered;  the  lesser  amount  of  soluble 
albuminoids  in  cow's  milk  must  be  made  up  and  their  relative 
proportion  to  the  casein  present  improved.  (3)  The  lesser 
amount  of  fat  and  the  unfavorable  proportion  of  fat  to  casein 
must  be  considered.  (4)  The  bacteria  must  be  rendered  harm- 
less. (5)  The  lesser  amount  of  sugar  must  be  compensated 
for.  (6)  The  salts  must  be  reduced  and  maternal  conditions 
imitated  as  closely  as  possible.  Monti  prefers  mixed  feeding 
to  the  exclusive  use  of  artificial  food,  and,  even  if  the  mother's 
milk  is  defective,  he  advises  to  wait  until  after  the  sixth  week 
before  giving  cow's  milk,  since  the  latter  will  be  better  toler- 
ated after  that  time. 

Monti  then  criticises  the  methods  of  Heubner,  Hoffmann, 
and  Soxhlet.  The  Heubner-Hoffmann  Mixture  is  presented  in 
a  very  concentrated  form  and  will  not  be  as  well  assimilated 
as  mother's  milk;  it  contains  too  little  soluble  albumin,  espe- 
cially for  the  first  months  of  life,  and  the  percentage  of  fat 
is  too  low.  Soxhlet  has  endeavored  to  supply  the  deficiency 
in  fat  by  the  addition  of  lactose.  The  amount  of  lactose 
needed  is  based  on  Buhner's  statement  that  one  hundred  parts 
of  fat  are  isodynamic  with  two  hundred  and  forty-three  parts 
of  sugar;  then  1.32  parts  of  fat  will  equal  3.19  parts  of  milk- 
sugar.  Cow's  milk  is  mixed  with  one-half  its  amount  of  12.3 
per  cent,  lactose  solution ;  this  gives  the  following  percentages : 
water  85.3,  proteids  2.37,  fat  2.46,  fat  represented  by  lactose 
1.32  (3.78  fat),  lactose  as  equivalent  for  absent  fat  3.19,  natu- 
ral lactose  content  3.25,  lactose  added  to  supply  deficiency 
2.96;  total  lactose  content  9.40.  In  Monti's  opinion,  Soxhlet's 
Mixture  contains  too  much  lactose.  This  is  apt  to  cause  diar- 
rhoea, and  is  therefore  not  a  good  substitute  for  fat. 

*  Wolf  and  Friedjung,  in  Monti's  clinic,  found  that  the  acidity  of  freshly 
milked  breast-milk  was  only  0.1,  tested  with  a  decinormal  soda  solution  ; 
whereas  the  acidity  of  raw  cow's  milk,  even  when  fresh,  amounted  to  1.1 
and  over.     (Eeported  at  Paris  Congress. ) 


MODERN    METHODS   OF   INFANT   FEEDING.  105 

Marfan' s  Mixture,  contains  too  much  lactose,  excessive  pro- 
teids, and  is  too  concentrated,  like  the  Heubner-Hoffmann 
Mixture.  Monti  therefore  condemns  it.  The  same  criticism 
applies  to  Siebert's  method. 

Monti  considers  that  Biedert,  in  his  Cream  Mixtures,  gives 
quantities  which  are  in  excess  of  the  actual  capacity  of  the 
stomach,  that  he  increases  the  proportion  of  proteids  too  rap- 
idly, and  that  he  gives  a  slight  excess  of  proteids  and  fat  during 
the  first  weeks  of  life.  Since  fresh  cream  varies  in  its  compo- 
sition, and  since  its  digestibility  is  altered  by  sterilization,  its 
use  should  be  restricted  to  those  cases  in  which  no  other  form 
of  milk  mixture  will  be  tolerated. 

Biedert's  Cream  Conserve,  if  well  prepared  and  completely 
sterile,  may  be  useful  for  a  certain  class  of  cases,  but  is  not 
adapted  to  take  the  place  of  fresh  milk ;  Heubner  expresses  the 
same  opinion. 

Vigier's  Humanized  Milk  (1893)  is  prepared  by  taking  a 
definite  quantity  of  milk  and  dividing  it  into  two  equal  parts. 
The  first  half  is  left  untouched;  the  second  half  stands  until 
the  cream  separates  completely,  when  the  cream  is  removed. 
The  skimmed  milk  is  coagulated  and  the  serum  obtained  is 
added  to  the  first  half,  as  is  the  separated  cream.  This  is 
sterilized.  Its  composition  is  as  follows,  according  to  Gau- 
trelet:  casein  2.36  per  cent.,  fat  3.75  per  cent.,  lactose  4.10 
per  cent.,  carbohydrates  0.81  per  cent.,  salts  0.7  per  cent. 

Monti's  Whey-Milk  Mixture  is  prepared  in  the  following 
manner.  The  whey  is  separated  from  one  litre  of  good  cow's 
milk,  rich  in  fat,  by  heating  the  same  to  35°  C.  and  adding 
one  gramme  of  French  lab-ferment  dissolved  in  forty  cubic 
centimetres  of  distilled  water.  The  latter  must  be  prepared 
freshly  each  time.  Allow  the  mixture  to  stand  until  it  be- 
comes jelly-like,  which  will  require  from  twenty-five  to  thirty 
minutes;  then  apply  heat  again  up  to  68°  C. ;  this  will  de- 
stroy the  lab-ferment.  Let  the  mixture  stand  till  cool  and 
filter  through  a  silk  cloth.     Whey  prepared  in  this  manner 


106  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

will  be  alkaline,  of  a  specific  gravity  of  from  1020  to  1027, 
and  will  contain :  casein  0.03  per  cent.,  soluble  albumin  from 
0.80  to  one  per  cent.,  fat  one  per  cent.,  sugar  from  4.5  to  five 
per  cent.,  salts  0.7  per  cent. 

For  the  first  five  months  of  life  a  mixture  of  equal  parts 
of  milk  and  whey  is  suitable;  to  older  infants,  if  not  im- 
proving as  they  should,  two  parts  of  milk  to  one  of  whey  should 
be  given.  After  cooling,  the  mixture  is  put  in  sterile  bottles 
and  pasteurized  in  the  Soxhlet  apparatus  for  from  ten  to 
fifteen  minutes  at  from  68°  to  70°  C. ;  it  is  then  cooled  to 
8C  C.  and  kept  at  this  temperature  until  used. 

The  composition  of  the  mixtures  will  be  as  follows : 


Casein.  Soluble  albumin.  Fat.           Sugar.          Salts. 

Per  cent.           Per  cent.  Per  cent.  Per  cent.  Per  cent. 

Mixture  No.  1 1.22           0.8-1.0  2.33       4.5-5        0.7 

Mixture  No.  II 1.61            0.8-1.0  3.11        4.5-5        0.7 


Monti  considers  that  these  mixtures  correspond  very  closely 
to  mother's  milk  in  their  proteid  percentages,  while  the  con- 
tent of  fat  and  sugar  is  lower  than  in  mother's  milk.  He 
believes  that  young  infants  thrive  better  on  low  fat  and  sugar 
percentages  in  artificial  feeding  than  when  these  ingredients 
are  present  in  larger  quantity.  Wolff  and  Paccini  have  ob- 
tained good  results  with  the  Monti  Mixture;  the  latter  used 
two  parts  of  whey  to  one  of  milk  rich  in  fat,  and  so  obtained 
a  mixture  containing  casein  one  per  cent.,  fat  three  per  cent., 
sugar  five  per  cent.,  and  rather  more  soluble  albumin  than  in 
the  Monti  Mixture. 

Schlossmann  has  emphasized  the  value  of  a  mixture  of 
whey  and  cow's  milk  from  the  theoretical  stand-point.  He 
thinks  that  the  addition  of  soluble  albumin  to  cow's  milk  has 
a  decided  influence  on  the  form  of  casein  precipitation.  To 
demonstrate  this,  he  took  a  cream  containing  seven  and  a  half 
per  cent,  fat  and  1.06  per  cent,  casein,  and  diluted  one-half 


MODERN    METHODS   OF   INFANT   FEEDING.  107 

the  quantity  with  equal  parts  of  water  and  the  other  half 
with  an  equal  part  of  one  per  cent,  serum-albumin  solution. 
The  latter  mixture  resembles  mother's  milk  in  its  chemical 
composition,  containing  3.75  per  cent,  fat  and  0.8  per  cent, 
casein  with  0.5  per  cent,  albumin.  The  first  half  of  the  mix- 
ture contains  just  as  much  fat  and  casein,  but  practically  no 
albumin.  These  mixtures  were  both  tested  with  artificial  gas- 
tric juice  in  an  incubator.  The  first  half  showed  the  for- 
mation of  large,  firm,  uneven  clots;  the  second  half  showed 
precipitated  casein  in  a  finely  divided  condition,  covering  the 
bottom  of  the  tube  as  a  finely  granular  deposit  of  soft  and  even 
consistency. 

Use  of  Diluents. — In  Monti's  opinion,  there  is  no  advantage 
to  be  gained  from  the  use  of  barley-water,  oatmeal-water,  etc., 
that  cannot  be  equally  well  obtained  with  plain  water.  The 
casein  clots  are  just  as  coarse  in  either  case,  and  digestion  is 
not  rendered  any  easier.  Moreover,  the  cereals  are  apt  to  cause 
meteorism  and  dyspeptic  symptoms,  especially  in  young  infants, 
and  have  no  especial  nutritive  value. 

At  the  Paris  Congress  of  1900  Monti  recommended  the  use 
of  sodium  carbonate  to  counteract  the  acidity  of  artificial  milk 
mixtures.  The  special  advantage  gained  by  the  use  of  whey- 
milk  mixtures  is  that  we  thereby  increase  the  proportion  of  solu- 
ble albumin  and  render  coagulation  by  lab-ferment  more  nearly 
like  that  which  occurs  in  the  stomach  of  the  breast-fed  infant. 
The  fat  content  of  cow's  milk  is  reduced  by  this  degree  of 
dilution,  and  to  make  up  the  deficiency  by  the  addition  of 
cream  cannot  be  recommended,  since  the  milk  will  then  con- 
tain relatively  too  many  fatty  acids.  The  infant  does  not 
digest  and  assimilate  cream  readily;  moreover,  the  fat  emul- 
sion is  affected  by  centrifugation,  so  that  large  drops  rise  to 
the  surface.  Two  per  cent,  is  a  quite  high  enough  fat  content, 
and  will  suffice  for  the  infant's  needs  if  the  correct  proportion 
of  proteids  and  sugar  is  given.  The  sugar  content  is  best  regu- 
lated by  the  addition  of  pure  whey. 


108  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

Monti  disapproves  of  sterilization  on  account  of  the  great 
changes  it  causes  in  milk;  he  prefers  to  heat  for  ten  minutes 
at  from  60°  to  70°  C,  and  then  to  cool  to  6°  C.  until  used. 
He  advises  to  allow  three-hour  intervals  between  feedings,  to 
suit  the  amount  to  the  capacity  of  the  stomach,  and  to  give 
proportionately  less  than  the  child  at  the  breast  would  take, 
since  cow's  milk  is  digested  with  more  difficulty. 

Ldhmann's  Vegetable  Milk,  according  to  Stutzer's  analyses, 
contains :  fat  twenty-five  per  cent.,  nitrogenous  substances,  prin- 
cipally plant-albumin,  ten  per  cent.,  sugar  and  other  non- 
nitrogenous  substances  38.5  per  cent.,  mineral  materials  1.5 
per  cent.,  water  twenty-five  per  cent.  It  is  asserted  that  the 
presence  of  vegetable  albumin  in  this  preparation  renders  the 
digestion  of  the  proteids  more  easy  by  furnishing  conditions 
approximating  precipitation  of  the  casein  of  mother's  milk 
by  lab  and  peptic  ferments.  Since  this  preparation  contains 
elements  which  are  not  found  in  mother's  milk,  it  cannot  be 
considered  a  normal  food. 

Backhaus  Milk  is  prepared  as  follows,  according  to  the  latest 
modifications  of  its  originator.16  Good  fresh  milk  is  separated 
by  centrifugation  into  cream  and  skimmed  milk;  a  mixture 
of  trypsin,  lab-ferment,  and  a  one-half  per  cent,  solution  of 
sodium  carbonate  is  then  heated  to  a  temperature  of  40°  C. 
and  added  to  the  skimmed  milk.  The  casein  is  first  coagulated 
by  the  lab,  then  the  trypsin  in  the  presence  of  the  alkali  re- 
dissolves  and  peptonizes  part  of  the  casein,  so  that  at  the  end 
of  half  an  hour  1.25  per  cent,  of  soluble  proteids  is  present. 
By  heating  to  80°  C.  the  action  of  the  enzyme  is  destroyed. 
The  separated  casein  is  then  removed  by  straining  or  by  cen- 
trifugation, and  cream  is  added  of  sufficient  concentration  to 
give  3.5  per  cent,  of  fat  and  0.5  per  cent,  of  casein;  finally 
one  per  cent,  of  lactose  is  added,  and  the  mixture  is  put  in 
separate  bottles  and  sterilized. 

This  preparation  is  practically  a  peptonized  milk,  and  time 
and  care  are  requisite  for  its  manufacture.    Biedert  and  Heub- 


MODERN   METHODS   OF   INFANT   FEEDING.  109 

ner  agree  that  the  natural  properties  of  milk  are  altered  by  the 
artificial  modifications  which  this  process  requires. 

Voltmer's  Mother's  Milk. — This  is  essentially  a  peptonized 
milk  which  has  received  additions  of  fat  and  sugar.  It  may 
be  made  fresh  or  as  a  conserve;  three  mixtures  of  different 
strengths  are  prepared.  The  composition  of  the  conserve  is 
liable  to  vary.  Heubner  considers  Voltmer's  Milk  valuable 
as  a  temporary  expedient  in  weakly  infants,  especially  for 
the  first  weeks  of  life.  Drews 45  thinks  that  it  is  adapted 
to  general  use,  both  for  sick  and  healthy  children,  and  that 
children  fed  on  it  are  no  more  liable  to  gastro-intestinal  dis- 
turbances than  those  at  the  breast.  He  cites  a  large  number 
of  cases. 

Loeflund's  Peptonized  Child's  Milk. — This  food  is  similar 
to  the  last-named  preparation,  and  can  be  used  temporarily 
in  like  manner.  In  Monti's  opinion,  it  has  no  advantages  over 
milk  which  is  peptonized  at  home. 

Loeflund's  Cream  Conserve  differs  from  Biedert's  in  con- 
taining maltose  instead  of  cane-sugar.  Its  analysis  reads: 
sugar  fifty  per  cent.,  fat  twenty-three  per  cent.,  proteids  five 
per  cent.,  ash  1.8  per  cent.,  water  20.2  per  cent.  In  Biedert's 
estimation,  the  presence  of  maltose  is  useful. 

Gaertner's  Milk  7  is  made  by  dividing  into  two  equal  parts  in 
the  separator  a  bulk  of  milk  diluted  equally  with  water.  The 
mixture  will  then  contain  nearly  all  the  fat  in  an  emulsified 
state,  and  one-half  the  quantity  of  proteids,  sugar,  and  salts  con- 
tained in  the  original  milk.  Apart  from  this,  Biedert  sees  no 
particular  advantage  in  Gaertner's  Milk  over  ordinary  cream 
mixtures.  Its  specific  gravity  ranges  from  1020  to  1030,  and 
an  analysis  of  its  contents  gives  the  following  average :  casein 
1.76  per  cent.,  fat  three  per  cent.,  sugar  2.4  per  cent.  It  is 
not  as  sweet  as  whole  milk,  but  the  taste  is  not  unpleasant; 
it  clots  in  smaller  flakes  than  cow's  milk. 

Marfan  has  observed  that  large  fat-droplets  collect  on  the 
surface  of  Gaertner's  Milk,  after  it  has  stood  for  some  time, 


110  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

and  form  a  yellow  skim.  After  several  hours  the  emulsion 
is  not  readily  re-formed. 

Monti  thinks  that  the  composition  of  Gaertner's  Milk  is 
inconstant;  the  reports  as  to  its  use  are  very  contradictory. 
Monti  asserts  that  the  centrifugation  disturbs  the  emulsion 
of  the  fat  and  causes  a  conglomeration  of  the  fat-globules. 
The  influence  of  the  fat-corpuscles  in  favoring  the  finer  coagu- 
lation of  the  casein  is  thus  impaired  and  absorption  is  hindered. 
Microscopical  examination  confirms  these  statements.  In 
Monti's  experience,  the  amount  of  faeces  is  apt  to  be  large  when 
infants  are  fed  on  Gaertner's  Milk.  Gaertner's  Milk  may  be 
used  temporarily  to  meet  definite  indications,  but  it  must  not 
be  considered  an  absolute  substitute  for  mother's  milk. 

Thiemich  and  Papiewsky,144  from  the  observation  of  thirty 
cases,  conclude  that  Gaertner's  Milk  can  be  used  when  there 
are  digestive  disturbances,  but  possesses  no  advantages  over 
dilutions  of  cow's  milk.  Czerny  thinks  that  Gaertner's  Milk 
and  Backhaus  Milk  are  not  efficient  substitutes  for  mother's 
milk  when  the  child  is  sick.  Fat  milk  is  useful  in  constipation, 
but  in  many  cases  it  is  not  well  borne.  Escherich  is  a  strong 
advocate  of  the  use  of  Gaertner's  Milk;  many  of  the  good 
results  which  he  obtained  were  in  the  case  of  healthy  infants 
who  had  just  been  weaned  or  who  were  getting  mixed  feeding. 

John  Lovett  Morse,  of  Boston,  in  "A  Consideration  of  Pro- 
fessor Gaertner's  Mother's  Milk,"  218  states  that  its  manufacture 
was  first  begun  in  this  country  in  1897.  His  conclusions  in 
regard  to  it  are  as  follows.  It  contains  only  the  constituents 
of  cow's  milk,  and  they  are  present  in  approximately  the  same 
proportions  as  in  human  milk;  but  they  are  not  constant,  are 
unknown  to  the  consumer,  and  are  insusceptible  of  modifica- 
tion. It  is  not  a  "  fresh"  food,  and  costs  as  much  or  more 
than  modified  milk  which  is  freshly  prepared  and  whose  pro- 
portions can  be  varied. 

Bieth's  Album ose  Milk  is  a  preparation  of  soluble  albumin, 
obtained  by  heating  egg  albumin  to  over  130°  C.     Cream  and 


MODERN    METHODS   OF   INFANT    FEEDING.  HI 

lactose  are  added  in  sufficient  quantity  to  make  a  product  simi- 
lar to  mother's  milk.  Monti  thinks  that  it  is  not  fit  to  be  a 
permanent  food,  but  agrees  with  Hauser  and  Baginsky  that 
it  may  give  good  results  in  isolated  cases. 

An  objection  which  applies  to  all  of  these  products  is  their 
cost.  Baginsky  deserves  credit  for  having  drawn  attention  to 
the  fact  that  these  foods  do  not  give  us  the  same  results  as  fresh 
milk;  marked  anaemia  and  scorbutic  affections  frequently  fol- 
low their  prolonged  use,  notwithstanding  that  the  children 
become  fat.  At  the  time  when  Liebig's  soup  and  condensed 
and  conserved  milk  preparations  were  in  general  use,  Monti 
often  noticed  that  children  fed  on  fresh  cow's  milk  were  not 
subject  to  anaemic  and  hemorrhagic  disorders.  (In  general  it 
may  be  said  of  all  these  preparations  that  none  of  them  justi- 
fies the  claims  put  forward  by  their  originators;  their  use 
must  necessarily  be  limited,  and  they  cannot  take  the  place 
of  properly  modified  cow's  milk. — Editors.) 

Steffens  Veal  Broth. — Steffen  has  lately  recommended  a 
mixture  of  cow's  milk,  veal  broth,  and  cream,  prepared  as 
follows.  One  hundred  and  forty  grammes  of  veal  are  added 
to  half  a  litre  of  water  and  cooked  for  from  a  half  to  three- 
quarters  of  an  hour,  boiling  water  being  added  from  time  to 
time  to  keep  up  the  original  quantity.  Salt  must  not  be  added. 
Veal  broth  and  milk  are  mixed  in  equal  parts,  and  to  each 
one  hundred  cubic  centimetres  of  the  mixture  five  cubic  centi- 
metres of  cream  and  3.8  grammes  of  lactose  are  added;  it  is 
then  sterilized  in  the  Soxhlet  apparatus.  This  mixture  con- 
tains: casein  1.8  per  cent.,  fat  3.1  per  cent.,  sugar  6.2  per 
cent.,  salts  0.45  per  cent. 

For  the  new-born  one  part  of  milk  and  three  parts  of  broth 
are  to  be  used;  this  will  contain  from  0.25  to  0.35  per  cent, 
of  salts,  which  is  greater  than  the  proportion  in  mother's  milk. 
For  the  later  periods  of  nursing  two  parts  of  milk  and  one 
part  of  broth  should  be  given;  if  there  is  constipation,  give 
less  milk  and  more  cream. 


112  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

This  preparation  has  a  pleasant  taste  and  smell  and  an 
amphoteric  reaction.  The  potassium  salts  in  veal  broth  in- 
crease the  alkalinity  and  facilitate  the  digestion  of  the  casein. 
Good  results  were  obtained  by  Steffen  in  his  own  experience 
of  ten  years;  his  father  used  the  veal  broth  for  twenty  years 
with  uniform  success.  Eickets  was  not  observed.  Both  sick 
and  healthy  children  took  the  mixture  well. 

Gregor.65  Malt  Soup. — Fresh  milk  is  obtained  directly 
from  the  farm  and  cooled  as  usual.  It  must  not  be  boiled. 
To  two-thirds  of  a  litre  of  water  heated  to  from  50°  to  60°  C. 
one  hundred  cubic  centimetres  of  Loeflund's  malt  extract  and 
ten  cubic  centimetres  of  an  eleven  per  cent,  solution  of  potas- 
sium carbonate  are  added.  At  the  same  time  fifty  cubic  centi- 
metres of  wheat  flour  are  added  to  one-third  of  a  litre  of  milk 
and  stirred  till  an  even  consistence  is  reached.  This  is  passed 
through  a  fine  sieve,  and  then  the  two  are  mixed  together  and 
brought  to  a  boil,  with  constant  stirring. 

If  one  litre  is  to  be  given  for  the  daily  portion,  heating  to  the 
boiling  point  requires  from  six  to  ten  minutes.  If  from  eight 
to  ten  litres  are  to  be  prepared,  twenty  to  thirty  minutes  are 
required.  To  avoid  overheating,  remove  the  heat  when  a  tem- 
perature of  94°  C.  is  reached  for  the  smaller  and  98°  C.  for 
the  larger  quantity.  The  mixture  as  prepared  is  thin  and 
has  a  good  spicy  taste  of  malt.  In  hot  weather  it  should  be 
kept  cool  and  in  sterile  bottles.  Sterilization  is  apt  to  cause 
separation  of  the  fat,  which  impairs  the  nutritive  value  of  the 
soup.  For  infants  from  one  and  a  half  to  three  months  of 
age  Gregor  uses  less  malt  extract  and  less  flour ;  and  for  infants 
from  nine  to  fifteen  months  of  age,  half  milk  and  half  maltose 
solution  (less  malt  is  used  to  make  the  solution).  Good  results 
were  obtained  with  this  preparation  in  over  seventy-five  per 
cent,  of  the  cases  which  presented  themselves  for  treatment 
(including  atrophic  cases  and  severe  gastro-intestinal  diseases), 
seventy-three  in  all.  Gregor  recommends  the  use  of  malt  soup 
in  diluted  form  to  infants  under  three  months,  provided  that 


MODERN    METHODS   OF   INFANT   FEEDING.  113 

its  administration  can  be  closely  supervised.  It  gives  good 
results  in  gastro-intestinal  affections,  malnutrition,  and  rickets, 
and  may  be  employed  when  the  child  is  weaned  or  for  mixed 
feeding.    Keller  also  uses  malt  soup  with  good  results. 

At  the  seventy-third  meeting  of  the  Society  of  German  Natu- 
ralists and  Physicians  Salge  presented  a  paper  on  the  use  of 
buttermilk  for  infant  feeding.142  He  considers  it  adapted  for 
the  child's  diet  when  convalescent  from  acute  digestive  disturb- 
ances and  in  atrophic  cases.  It  may  be  added  to  malt  soup  or 
as  a  supplement  to  breast-milk.  It  must  be  fresh  and  clean  and 
carefully  prepared  from  sour  cream.  The  average  formula  will 
be:  from  2.5  to  2.7  per  cent,  proteids,  0.5  to  one  per  cent,  fat, 
and  2.8  to  three  per  cent,  sugar.  According  to  Eubner,  one 
litre  will  furnish  seven  hundred  and  fourteen  calories. 

One  hundred  and  nineteen  cases  were  fed  on  it  at  the  Charite 
(Berlin) ;  of  these,  eighty-five  gave  favorable  results.  The 
faeces  contained  many  lactic  acid  bacilli  and  were  of  firm  con- 
sistence; in  some  cases  there  was  constipation.  To  each  litre 
of  buttermilk  fifteen  grammes  of  meal  and  sixty  grammes 
of  cane-sugar  were  added,  and  it  was  then  heated  slowly  to 
boiling.  Investigations  as  to  the  absorption  of  proteids  and 
fat,  which  are  not  as  yet  completed,  show  that  the  greater 
portion  of  them  is  absorbed. 

Schlossmann  reported  at  the  same  meeting  that  he  had  fed 
one  hundred  and  fifty  infants  on  buttermilk  with  good  results. 
If  the  gain  in  weight  was  not  satisfactory,  he  added  cream. 

Filatow,58  of  St.  Petersburg,  advises  to  give  the  new-born 
infant  milk  diluted  three  times  with  a  solution  of  oatmeal-, 
rice-,  or  barley-water,  adding  two  or  three  teaspoonfuls  of 
sugar  to  each  half-pint.  From  one  to  three  months  give  one 
part  of  milk  to  two  of  water,  from  three  to  four  months  equal 
parts,  from  four  to  six  months  two  parts  of  milk  to  one  part 
of  water,  and  after  six  months  pure  milk.  This  scheme  can, 
of  course,  be  varied  to  suit  the  infant's  development  and  its 
powers  of  digestion.    A  child  below  five  months  of  age  can  take 

8 


114  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

at  one  time  as  many  ounces  as  its  age  pins  one, — e.g.,  at  three 
months  fonr  ounces,  at  five  months  six  ounces,  etc.  From 
six  to  twelve  months  give  six  ounces  at  a  feeding.  Up  to  the 
second  month  feed  every  two  hours  in  the  day  and  twice  at 
night;  from  two  to  four  months  feed  every  three  hours  in 
the  day  and  once  at  night, — seven  meals  in  all.  After  this 
feed  six  times  in  the  twenty-four  hours.  No  starchy  food 
should  be  given  before  the  fourth  month.  Cleanliness  in  ob- 
taining and  handling  the  milk  is  essential.  In  case  the  child 
cannot  take  cow's  milk,  try  Biedert's  Cream  Mixture  or  Gaert- 
ner's  Milk. 

Schlesinger,139'  227  of  Breslau,  recommends  the  use  of  pure 
undiluted  cow's  milk  for  infant  feeding ;  this  may  be  sterilized 
if  necessary.  The  calorie  value  of  woman's  milk  is  almost  iden- 
tical with  that  of  undiluted  cow's  milk.  The  more  cow's  milk 
is  diluted  the  lower  will  its  food  value  fall  and  the  more  in- 
sufficient will  it  become  for  the  infant's  needs.  Dilution  with 
water  does  not  render  the  casein  more  digestible;  the  fact  is, 
by  diluting  milk  from  two  to  three  times  we  simply  flood  the 
system  with  water,  for  the  child  has  to  take  a  much  larger 
quantity  of  food  to  get  the  necessary  quotient  for  its  proper 
growth.  Such  a  flooding  of  the  system  entails  greater  work  on 
the  part  of  the  organs  of  digestion  and  assimilation,  and  often 
leads  to  marked  dyspeptic  disturbances,  gastric  dilatation,  and 
finally  atrophy.  Schlesinger  therefore  advises  to  give  small 
quantities  of  whole  milk  even  during  the  first  month  of  life. 

Czerny  34  also  believes  that  we  injure  the  child  by  giving 
too  weak  dilutions,  and  that  some  of  the  normal  salts  in  the 
economy  will  be  washed  out  by  an  excessive  administration 
of  water.  The  danger  of  giving  too  much  proteids  is  still 
greater,  however;  Czerny  therefore  agrees  with  Heubner  that 
we  should  give  concentrated  mixtures  containing  a  moderate 
amount  of  proteids.  The  intervals  between  feedings  should  be 
long, — at  least  four  hours. 

Keller  84  considers  that  in  the  normal  artificially  fed  in- 


MODERN    METHODS   OF   INFANT   FEEDING.  115 

fant  the  stomach  contents  are  evacuated  about  three  hours 
after  taking  food;  free  hydrochloric  acid  is  present  only  two 
hours  later.  It  has  been  observed  that  constant  burdening  of 
the  stomach  with  food  diminishes  the  secretion  of  hydrochloric 
acid  and  the  gastric  motility.  In  sick  children  we  often  find 
food  remnants  in  the  absence  of  hydrochloric  acid  as  long  as 
four  or  five  hours  after  a  meal.  An  interval  long  enough  to 
allow  the  stomach  to  empty  itself  completely  seems  to  be 
necessary  for  the  re-establishment  of  the  secretory  and  motor 
functions  of  the  stomach. 

The  addition  of  maltose  to  milk  diminishes  the  destruc- 
tion of  the  albuminoid  substances  in  the  economy,  and  per- 
mits the  maintenance  of  nitrogenous  equilibrium  without  the 
necessity  for  excessive  proteids  in  the  diet.  It  is  therefore 
the  best  form  in  which  to  administer  carbohydrates  to  in- 
fants. 

Schmid-Monnard,127  of  Halle,  does  not  believe  in  the  use 
of  food  which  has  been  subjected  to  prolonged  heat ;  fresh  milk 
must  be  employed  for  the  purposes  of  infant  feeding,  to  which 
cream,  water,  and  sugar  are  to  be  added.  There  are  marked 
variations  in  the  quantity  of  food  required  by  artificially  fed 
as  well  as  breast-fed  babies;  the  daily  number  of  calories  re- 
quired remains,  however,  about  the  same, — namely,  one  hundred 
and  thirty-three  calories  per  kilogramme  of  body  weight  for 
artificially  fed  and  ninety-nine  calories  per  kilogramme  for 
breast-fed  infants.  The  number  of  calories  needed  during 
the  first  six  months  varies  from  one  hundred  and  seventeen  to 
one  hundred  and  thirty-nine  per  day  for  each  kilogramme  of 
body  weight  in  bottle-fed  babies;  the  gain  in  weight,  which 
diminishes  with  the  age  of  the  child,  amounts  to  thirty-five 
grammes  daily  during  the  first  month,  16.3  grammes  during 
the  third  month,  and  8.1  grammes  during  the  sixth  month. 
There  are  great  variations  in  the  weight  increase,  although  the 
average  gain  is  essentially  the  same  as  in  breast-fed  babies. 
Notwithstanding  the  greater  number  of  calories  supplied,  the 


116  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

body  weight  of  bottle-fed  infants  does  not  increase  proportion- 
ally as  fast  as  that  of  sucklings. 

The  proper  food  for  strong  children  up  to  six  months  of 
age  is  milk  diluted  one-half  or  two-thirds,  with  sugar  added; 
for  weaker  children  milk  diluted  one-third,  with  cream  and 
sugar  added.  Schmid-Monnard  thinks  that  infants  of  low 
weight  and  delicate  constitution  assimilate  proteids  better  than 
stronger  infants,  in  whom  the  casein  passes  more  or  less  un- 
digested through  the  intestinal  tract.  Even  in  the  most  dilute 
mixtures  there  are  enough  proteids,  but  not  enough  fat  and 
sugar  to  supply  the  needs  of  the  body.  Whereas  the  nursing 
child  takes  in  its  first  year  three  and  a  half  kilogrammes  of 
proteids,  twelve  kilogrammes  of  fat,  and  twenty  kilogrammes 
of  sugar,  artificially  fed  babies  get  in  their  first  six  months 
five  and  a  half  kilogrammes  of  proteids,  six  and  two-thirds 
kilogrammes  of  fat,  and  ten  and  a  half  kilogrammes  of  sugar, 
— enough  proteids,  but  scarcely  enough  fat  and  sugar. 

Marfan  105  concludes,  on  the  basis  of  his  clinical  experience, 
that  healthy  infants  can,  as  a  rule,  digest  pure  sterilized  cow's 
milk  after  the  fourth  to  the  fifth  month;  before  that  time 
even  the  purest  milk  should  not  be  given  undiluted.  He  has 
found  that  healthy  infants  under  four  or  five  months,  who  are 
fed  on  pure  cow's  milk,  fall  into  one  of  three  classes : 

I.  The  first  and  smallest  class  show  signs  of  chronic  gastro- 
intestinal inflammation  with  general  atrophy  and  cachexia. 

II.  The  second  class  show  no  anomalies,  especially  those 
infants  who  have  had  the  breast  for  the  first  few  weeks. 

III.  The  third  and  largest  class,  which  includes  those  in 
especial  who  have  received  nothing  but  pure  cow's  milk  since 
birth,  are  apparently  well,  but  on  examination  we  find  them 
suffering  from  constipation;  the  stools  are  pasty  and  putty- 
colored,  and  constipation  alternates  with  diarrhoea;  vomiting 
is  frequent.  It  is  probable  that  this  dyspepsia  is  due  to  a  mild 
form  of  gastro-enteritis  (pure  cow's  milk  dyspepsia).  Variot 
advises  that  cow's  milk  should  be  diluted  three  or  four  times 


MODERN   METHODS   OF   INFANT   FEEDING.  117 

during  the  first  weeks  of  life;  a  little  sugar  should  be  added. 
Gauchas  believes  that  cow's  milk  should  be  diluted  during  the 
first  four  or  five  months  of  the  child's  existence. 

The  method  which  Marfan  has  followed  during  recent  years 
consists  in  the  use  of  milk  diluted  with  boiled  water  to  which 
enough  sugar  is  added  to  make  a  teu  per  cent,  solution.  For 
the  first  five  or  six  days  the  mixture  should  be  half  milk  and 
half  sugar  solution;  from  this  time  up  to  four  or  five  months 
the  mixture  should  be  two-thirds  milk  and  one-third  sugar 
solution;  after  this  time  Marfan  tries  to  give  whole  milk, 
with  enough  sugar  added  to  bring  the  sugar  percentage  up 
to  six.  If  digestive  disturbances  arise,  he  dilutes  the  milk 
three  or  four  times  with  sugar-water.  The  milk  should  be 
sterilized  at  100°  C.  in  small  bottles  on  the  "bain-marie/'  after 
mixing  with  sugar-water. 

Marfan  does  not  consider  that  it  is  necessary  to  reduce  the 
casein  to  the  proportions  found  in  mother's  milk,  the  only 
object  of  dilution  being  to  render  the  casein  more  digestible. 
By  adding  ten  per  cent,  sugar  solution  we  can  to  a  certain 
extent  supply  the  deficit  in  fat.  His  mixture  of  two  parts 
of  milk  and  one  part  of  ten  per  cent,  sugar  solution  contains 
2.2  per  cent,  casein,  seven  per  cent,  sugar,  and  2.4  per  cent, 
fat,  with  0.4  per  cent,  salts.  By  giving  a  mixture  of  this 
strength  we  avoid  overcharging  the  stomach  with  too  great  a 
quantity  of  diluted  milk.  It  is  important  to  use  a  milk  which 
is  rich  in  fat  (from  3.8  to  four  per  cent.).  Marfan  doubts  the 
advisability  of  adding  salt,  sodium  bicarbonate,  or  lime-water. 
Salt  is  only  useful  in  certain  cases  of  indigestion,  to  combat 
lientery,  anorexia,  and  constipation.  Milk  should  not  be  alka- 
lized before  sterilization,  and  Marfan  considers  it  superfluous 
except  in  certain  cases  of  gastric  disturbance.  His  only  ob- 
jection to  this  method  is  that  the  gain  in  weight  is  slightly 
less  than  in  the  case  of  breast-fed  infants. 

Centrifugation  modifies  the  fat  of  milk  so  as  to  render  it 
difficult  of  digestion.     This  explains  its  failure  in  cases  of 


118  THE   ARTIFICIAL   FEEDING   OF    INFANTS. 

digestive  disturbances.  Marfan  advises  that  the  feedings  should 
always  be  three  hours  apart  to  allow  of  perfect  digestion. 

Comby  229  advises  that  milk  should  be  diluted  in  the  follow- 
ing manner: 

First  month One-half  milk  and  one-half  water. 

Second  month  . . .  Two-thirds  milk  and  one-third  water. 

Third  month Three-quarters  milk  and  one-quarter  water. 

Fourth  month  . . .  Pure  milk. 

To  each  one  hundred  and  fifty  cubic  centimetres  of  the 
mixture  he  adds  4.5  cubic  centimetres  of  sugar.  Ordinary 
sugar  or  lactose  may  be  used.  Water  is  the  best  diluent.  The 
mixture  should  not  be  too  -dilute,  for  in  that  case  the  child 
is  likely  to  take  too  great  a  quantity  in  its  efforts  to  get  the 
amount  of  nourishment  required.  Of  the  alkaline  diluents 
lime-water  is  the  best.  Comby  believes  in  mixed  feeding  if 
the  breast-milk  is  deficient.  At  six  months  the  breast-milk 
almost  always  has  to  be  supplemented.  Panada  may  be  used 
for  weaning;  it  is  made  by  thoroughly  soaking  toasted  bread 
or  well-cooked  biscuit  in  water,  adding  butter  and  salt,  and  then 
boiling.  It  may  be  thickened  with  egg.  Bacahout,  salep,  and 
phosphatine  salieres  (a  mixture  of  rice,  tapioca,  potato,  and 
arrowroot  in  equal  parts  plus  cocoa,  sugar,  and  phosphate 
of  lime;  of  the  latter  ingredient  0.20  gramme  to  each  five 
cubic  centimetres  of  gruel)  may  be  used  to  thicken  milk, 
broths,  and  gruels,  and  are  well  liked  by  children.  Arrow- 
root is  poor  in  albuminous  substances;  it  should  not  be 
employed  early,  as  indigestion,  anaemia,  scurvy,  etc.,  result. 
These  preparations  are  to  be  used  in  weaning,  always  with 
fresh  milk. 

Budin  23  advises  the  use  of  pure  cow's  milk,  sterilized  at 
100°  C,  kept  in  separate  bottles,  and  used  within  twenty-four 
hours.  Occasionally  it  is  necessary  to  dilute  milk  with  water 
for  infants  under  two  months;    or  one  can  try  Vigier's  Hu- 


MODERN   METHODS   OF   INFANT   FEEDING.  119 

manized  Milk,  Backhaus  Milk,  or  Gaertner's  Milk.    Variot  also 
recommends  the  employment  of  sterilized  whole  milk. 

Boissard  21  uses  humanized  milk  in  which  the  casein  per- 
centage is  reduced  to  1.7  instead  of  3.6;  this  is  accomplished 
by  the  same  method  which  Gaertner  employs  in  preparing 
Mother's  Milk.  The  milk  should  be  heated  to  38°  C.  and  thor- 
oughly mixed  by  shaking  before  it  is  used.  The  author  thinks 
that  pasteurization  at  home  would  give  more  satisfactory  re- 
sults than  sterilization,  since  the  former  does  not  alter  the 
taste  or  composition  of  the  milk. 

Jacobi.76  For  the  purposes  of  nutrition  nature  allows  great 
latitude,  since  the  mother's  milk  constantly  changes  from  one 
minute  to  another,  from  morning  till  night,  depending  on  her 
diet,  state  of  health,  menstruation,  and  stage  of  lactation, — 
and  still  the  baby  thrives  !  Thus  there  is  no  sameness  in  human 
milk,  and  for  that  reason  no  possibility  of  arranging  a  perfect 
and  uniform  substitute  for  every  kind  of  it. 

The  caseins  of  mother's  milk  and  cow's  milk  differ  both  chem- 
ically and  physiologically.  These  differences  have  been  studied 
extensively  since  Hammarsten  first  wrote  thirty  years  ago, 
but  to  this  moment  it  is  not  clear  whether  the  albuminoid 
which  is  found  besides  casein  is  coordinate  to  it  or  derived 
from  it.  There  are  some  modern  observations  which  seem  to 
prove  conclusively  that  the  caseins  of  different  animals  cannot 
be  identical  any  more  than  are  their  blood-cells.  Wassermann 
and  A.  Schiitze  found  that  by  injecting  different  animals  daily 
with  sterilized  cow's  milk  for  a  fortnight,  their  blood-serum 
acquired  the  property  of  coagulating  the  proteids  of  cow's  milk, 
but  not  those  of  another  animal.  Similarly,  other  milks  exer- 
cised a  specific  coagulating  effect  upon  their  own  proteids. 

There  need  be  no  better  proofs  of  the  differences  between  the 
caseins  of  different  milks;  every  animal  has  its  own  specific 
milk  adapted  to  the  wants  of  its  own  offspring,  and  the  belief 
that  one  milk  can  be  substituted  for  another  is  a  mistake. 


120  THE   ARTIFICIAL   FEEDING   OF  JNFANTS. 

In  regard  to  various  methods  of  feeding,  Jacobi  asks  whether 
it  is  true  that  iron-clad  rules  as  to  the  composition  of  a  sub- 
stitute are  to  the  point  or  justified.  In  his  opinion,  only  one 
great  progress  has  been  made  in  infant  feeding  these  dozens 
of  years, — namely,  the  more  or  less  universal  introduction  of 
the  practice  of  heating  cow's  milk  and  all  other  substances 
employed  in  infant  feeding. 

In  Jacobi's  experience  with  Laboratory  Milk,  many  infants 
thrive  on  it  for  a  certain  time,  for  the  mixture  is  sterilized  in 
single  feeding-bottles  holding  prescribed  quantities,  but  very 
many  become  more  or  less  rachitic.  He  has  frequently  seen 
mild  forms  of  craniotabes  which  required  the  addition  of  ani- 
mal food,  phosphorus,  etc. 

There  can  be  no  doubt  that  the  end  aimed  at  by  Kotch 
is  partly  obtained  by  securing  a  reliable  and  approximately 
fresh  milk,  and  by  sterilizing  it  in  small  portions.  In  that  he 
has  performed,  with  Coit  and  others,  most  valuable  educational 
and  missionary  work. 

The  dilutions  Jacobi  employs  vary  from  four  to  six  parts 
of  diluent  to  one  part  of  milk  for  the  new-born,  down  to  equal 
parts  at  six  months.  In  general  he  believes  that  the  propor- 
tion of  casein  should  not  exceed  one  per  cent,  during  the  early 
months. 

Jacobi  prefers  cane-sugar  to  lactose  in  the  preparation  of 
his  mixtures,  since  it  is  not  so  easily  transformed  into  lactic 
and  other  acids.  The  identity  of  the  lactose  in  mother's  milk 
and  cow's  milk  has  not  been  proved,  and  the  lactose  of  the 
market  is  quite  often  impure.  That  alone  makes  it  desirable 
or  advisable  to  substitute  cane-sugar,  if  this  affords  the  same 
advantages. 

After  eight-tenths  of  one  per  cent,  of  the  lactose  contained 
in  whole  milk  is  changed  in  the  stomach  into  lactic  acid,  its 
production  ceases.  Ordinarily  this  limit  is  reached  when  about 
one-fourth  of  the  milk-sugar  has  been  so  converted.  But 
if  at  that  time  lactic  acid  be  neutralized  by  an  alkali,  more 


MODERN   METHODS   OF   INFANT   FEEDING.  121 

milk-sugar  is  changed  into  lactic  acid.  Therefore  it  appears 
that  in  every  preparation  of  cow's  milk  selected  for  the  use 
of  the  infant  there  is  enough  milk-sugar  to  supply  the  needs 
of  the  digestive  processes. 

Finally,  he  adds,  the  antifermentative  action  of  lactic  acid 
displayed  during  the  putrefaction  of  albuminoids  is  shared 
by  other  sugars  and  by  starch,  and  Miura  has  proved  that  the 
small  intestines  of  the  foetus  and  new-born  contain  an  inverting 
ferment  which  renders  possible  the  absorption  of  cane-sugar. 
To  repeat,  a  milk  mixture  which  contains  twenty-five  per  cent, 
of  milk  will  furnish  enough  milk-sugar  for  the  purposes  of 
lactic  acid  production  and  of  digestion. 

The  proportion  of  fat  in  an  infant's  diet  should  never  ex- 
ceed that  found  in  mother's  milk.  According  to  Heubner, 
5.9  per  cent,  (in  the  breast-fed  infant),  5.3  per  cent,  (in  the 
infant  fed  on  cow's  milk),  and  fifteen  per  cent,  (in  infants 
with  weak  digestion)  of  the  fat  introduced  in  the  food  is  ex- 
pelled undigested.  If  so  much  is  expelled  unchanged,  Jacobi 
does  not  consider  that  the  addition  of  cream  to  the  milk  mix- 
ture is  quite  a  sine  qua  non.  "  In  the  face  of  these  data,  cow's 
milk  fat  is  added  to  infant  food  equally  in  winter  and  in  sum- 
mer, while  the  Esquimaux  of  the  cold  climate  have  told  us 
long  ago  that  it  is  they  that  require  fat,  and  the  ancient  He- 
brews of  the  torrid  zone  that  it  should  be  prohibited  in  broiling 
climates  or  seasons.  Nor  has  the  frequency  of  (Biedert's) 
fat  diarrhoea,  which  has  been  noticed  even  in  infants  nursed 
by  their  own  mothers,  been  a  warning."  Moreover,  the  fat 
of  cow's  milk  differs  from  that  of  mother's  milk.  The  latter 
has  more  oleic  acid  and  less  volatile  acids  than  cow's  milk. 
Mother's  milk  contains  its  fat  in  finer  emulsion  and  has  from 
two  to  four  times  as  many  fat-globules  as  are  found  in  an 
equally  fat  cow's  milk  (Schlossmann).  It  is  reasonable  to 
assume  that  such  fine  fat-globules  may  be  absorbed  directly 
through  the  epithelia  of  the  intestinal  villi.  The  fat  of  cow's 
milk,  before  it  is  used,  undergoes  changes:    when  raised  by 


122  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

the  gravity  process,  it  is  apt  to  acidulate ;  when  sterilized  and 
centrifugated,  it  is  changed  chemically  and  physically;  when 
frozen,  it  separates  from  the  milk  and  does  not  mix  again. 
All  these  facts  have  led  Jacobi  to  reduce  rattier  than  to  increase 
the  fat  of  cow's  milk  used  for  infant  feeding. 

Jacobi  is  a  firm  believer  in  dilution,  and  has  found  that 
"  there  is  not  a  more  frequent  cause  of  dyspepsia,  except  ex- 
cessive summer  heat  and  senseless  amounts  of  pasty  amylaceous 
foods,  than  undiluted  cow's  milk  in  the  well  and  the  sick 
infant."  The  objections  made  on  the  ground  that  large 
amounts  of  food  may  cause  gastric  dilatation,  he  believes,  are 
theoretical.  The  rapid  action  of  the  almost  vertical  stomach 
and  the  rapid  absorption  from  it  and  from  the  intestine  of 
fluids  containing  salts  and  sugar  render  gastric  dilatation  "  very 
improbable — probably  impossible."  Water  does  not  act  like 
bulky  indigestible  food,  and  diabetics  may  drink  daily  from 
five  to  ten  litres  of  it  for  years  without  dilatation  of  the  stom- 
ach from  that  cause.  Furthermore,  a  great  quantity  of  water 
is  needed  to  assist  in  pepsin  digestion.  In  artificial  digestion, 
albumin  often  remains  unchanged  until  large  quantities  of 
acidulated  water  are  supplied.  Peptones  require  water  to 
facilitate  their  solution  and  absorption;  moreover,  it  is  cer- 
tainly true  that  large  amounts  of  water  passing  through  the 
kidneys  reduce  the  danger  of  uric  acid  infarcts,  the  results 
of  which  are  gravel,  renal  calculus,  and  nephritis. 

Where  plain  water  is  to  be  used,  it  will  generally  give  greater 
satisfaction  if  it  has  previously  been  boiled,  in  the  case  of 
very  young  infants,  even  if  there  be  no  apparent  urgency 
for  it. 

Dilutions  with  plain  water  may  seem  to  be  harmless;  in 
many  instances  children  thrive  on  them.  More,  however,  only 
appear  to  do  well,  for  increasing  weight  and  obesity  are  not 
synonymous  with  health  and  strength.  A  better  way  to  dilute 
cow's  milk,  and  at  the  same  time  to  render  its  casein  less 
liable  to  coagulate  in  large  lumps,  is  to  add  decoctions  of  the 


MODERN   METHODS   OF   INFANT   FEEDING.  123 

cereals.  Those  which  contain  the  least  starch  are  to  be  pre- 
ferred,— barley  where  there  is  a  tendency  to  diarrhoea,  oatmeal 
in  cases  of  constipation.  Schiffer,  Korowin,  and  Zweifel  have 
proved  that  infants,  even  from  birth,  can  transform  small 
amounts  of  starch  into  sugar  by  the  action  of  the  saliva.  Be- 
ginning with  the  fourth  week,  the  pancreatic  secretion  also 
possesses  diastatic  properties.  "  Not  only  does  amylum  save 
feeding  with  albuminoids  (Voit),  the  excess  of  which  leads 
so  easily  to  intestinal  putrefaction;  not  only  is  it,  together 
with  other  carbohydrates,  the  principal  source  of  muscular  force 
in  general  and  of  the  heart  in  particular  (mainly  in  the  acute 
diseases  and  probably  better  than  alcohol)  ;  but  it  (amylum) 
also  acts  as  a  direct  intestinal  antiseptic." 

The  physiological  effect  of  sodium  chloride  is  very  important, 
no  matter  whether  it  is  directly  introduced  through  the  woman's 
milk  or  added  as  a  condiment  to  cow's  milk;  the  latter  con- 
tains more  potassium  than  sodium,  and  ought  never  to  be 
given  without  the  addition  of  table  salt.  There  is  no  better 
protection  to  the  epithelia  and  cell  fluids  than  sodium  chloride. 
Excretion  and  secretion  are  to  a  great  extent  rendered  safe 
by  it;  it  serves  directly  as  an  excitant  to  the  secretion  of 
the  gastric  glands  and  facilitates  digestion.  Another  very  im- 
portant fact  is  this :  the  addition  of  sodium  chloride  prevents 
the  solid  coagulum  of  milk  by  either  rennet  or  gastric  juice. 
Therefore  it  should  always  be  added  to  mixtures  of  cow's  milk, 
and  should  also  be  given  in  cases  nourished  on  the  breast,  if 
the  mother's  milk  behaves  like  cow's  milk  in  regard  to  solid 
curdling.  Where  decoctions  of  cereals  are  used,  the  percentage 
of  salt  should  be  much  higher. 

It  is  to  be  questioned  how  much  alkalization  can  be  ef- 
fected by  the  addition  of  lime-water  in  five  per  cent,  strength 
(as  commonly  advised).  At  59°  F.  it  contains  0.17  per  cent, 
of  lime,  in  rising  temperatures  less,  and  at  the  boiling  point 
0.13  per  cent.  An  experiment  with  good  cow's  milk  showed 
that  lime-water  failed  to  overcome  acidity. 


124  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

To  render  milk  distinctly  alkaline  with  sodium  bicarbonate 
may  be  a  grave  error.  The  very  bacilli  which,  with  their  spores, 
resist  boiling  to  an  unusual  degree  thrive  best  in  an  alkaline 
milk. 

The  new-born  should  have  its  milk  boiled,  sugared,  salted, 
and  mixed  with  from  four  to  five  times  its  amount  of  barley- 
water.  At  six  months  give  equal  parts.  Gum  arabic  and  gela- 
tin are  also  useful,  not  only  as  diluents  but  also  as  nutrients. 
No  single  method  is  to  be  considered  infallible;  each  case  has 
its  own  requirements. 

After  boiling,  milk  should  be  kept  in  a  clean  bottle  containing 
from  three  to  six  ounces,  filled  to  the  cork  and  inverted  in  a 
cool  place.  Before  being  used,  it  should  be  heated  on  a  water- 
bath.  By  repeating  this  heating  of  the  whole  amount  several 
times  a  day,  fermentation  will  be  retarded  and  the  digestibility 
of  the  milk  improved. 

Starr.133  Success  in  hand  feeding  depends  on  the  adminis- 
tration as  well  as  on  the  proper  modification  of  the  cream 
and  milk  mixtures, — i.e.,  care  of  the  bottle,  nipples,  etc.  The 
separate  preparation  of  each  meal  is  important,  as  changes 
occur  in  the  food  if  it  is  all  mixed  at  the  same  time.  The 
child  should  occupy  a  half  reclining  position  when  nursing, 
to  prevent  air  from  being  swallowed,  and  from  five  to  fifteen 
minutes  should  be  allowed  for  each  meal.  Even  the  youngest 
infants  require  water  several  times  a  day,  and  the  necessity 
increases  with  age.  During  the  summer  water  cooled  with 
ice  may  be  allowed  without  harm;  at  other  times  water  should 
not  be  too  cold. 

To  render  cow's  milk  as  nearly  like  human  milk  as  possible 
it  is  necessary  to  reduce  the  percentage  of  casein,  to  increase 
the  proportion  of  fat  and  sugar,  and  to  overcome  the  tendency 
of  the  casein  to  coagulate  in  large  masses.  To  accomplish  this 
we  dilute  with  water,  add  fat  in  the  form  of  cream,  and  either 
cane-sugar  or  lactose.  The  latter  is  greatly  to  be  preferred  to 
cane-sugar,  as  it  is  less  apt  to  ferment  and  contains  the  salts 


MODERN    METHODS   OF    INFANT    FEEDING. 


125 


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126  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

of  milk,  which  are  of  nutritive  value.  Starr  recommends  the 
use  of  lime-water,  one  to  three,  as  it  causes  clotting  of  the 
casein  to  take  place  more  slowly  and  in  smaller  masses.  A 
saccharated  solution  of  lime  is  even  better  than  lime-water. 
Instead,  from  two  to  four  grains  of  sodium  bicarbonate  may 
be  used  to  each  bottle. 

Starr  believes  that  barley-water  and  other  attenuants  act 
mechanically  by  preventing  the  agglutination  of  casein  par- 
ticles in  large  masses.  The  former,  to  be  efficient,  should  be 
used  in  the  same  proportion  and  in  place  of  water.  Gelatin 
may  also  be  used.  Except  when  employed  as  mechanical  dilu- 
ents, starches  should  not  be  used  before  the  fourth  month, 
since  they  differ  so  materially  from  human  milk  in  composition 
that  they  are  apt  to  lead  to  digestive  disturbances. 

At  the  second,  third,  and  fourth  meals  two  teaspoonfuls  of 
a  reliable  infant's  food  may  be  added,  the  milk-sugar  being 
omitted.  Baked  wheat  or  barley  flour  may  be  used  instead 
if  there  is  a  tendency  to  diarrhoea. 

We  may  give  as  substitutes  for  cow's  milk  equal  parts  of 
veal  broth  and  barley-water,  or  of  whey  and  barley-water  plus 
a  small  amount  of  lactose ;  also  a  teaspoonful  of  raw  beef  juice 
diluted.  Sometimes  it  is  sufficient  in  cases  of  indigestion  to- 
wards the  end  of  the  first  year  to  reduce  the  strength  of  the  food 
to  that  suited  for  a  child  from  two  to  three  months  younger. 

Starr.135  "  Laboratory  Milk  is  theoretically  the  most  per- 
fect substitute  for  normal  human  milk  that  science  has  yet 
devised.  But  unfortunately  clinical  experience,  in  my  own 
practice  at  least,  does  not  bear  this  theory  out."  The  following 
is  a  generalization  of  the  results  of  over  two  years'  study  of  the 
use  of  Laboratory  Milk  in  substitute  feeding. 

I.  Three  cases  could  be  termed  satisfactory, — i.e.,  healthy 
infants  continuously  fed  on  Laboratory  Milk  from  shortly  after 
birth  to  the  time  of  beginning  mixed  diet. 

II.  Sixteen  cases  were  partially  satisfactory, — i.e.,  infants  in 
whom  Laboratory  Milk  was  used  for  some  time — from  six 


MODERN    METHODS   OF   INFANT   FEEDING.  127 

months  to  a  year — without  producing  active  illness,  but  gradu- 
ally inducing  unhealthy  conditions  which  necessitated  a  change 
of  food. 

III.  Thirty-five  cases  were  unsatisfactory, — i.e.,  infants  in 
whom  Laboratory  Milk  had  to  be  discontinued  on  account  of 
the  onset  of  some  acute  disorder  of  undoubted  dietetic  origin. 

The  unhealthy  conditions  referred  to  in  the  second  class 
presented  a  very  uniform  group  of  symptoms, — namely,  pallid, 
dry  skin;  dry,  lustreless  hair;  soft,  flabby  muscles ;  indifferent 
appetite;  inactive,  not  decidedly  constipated,  bowels;  clay- 
colored  evacuations;  light-colored  urine;  listlessness  and  dis- 
inclination to  play;  peevishness  and  restless  sleep — in  a  word, 
the  features  of  malnutrition.  With  the  flabbiness  there  is  not 
always  emaciation,  but  the  two  conditions  are  often  asso- 
ciated. 

Although  scurvy  is  an  exceptional  result  of  laboratory  feed- 
ing, Starr  has  personal  knowledge  of  one  undoubted  case  in 
which  orange  juice  removed  the  symptoms,  but  where  the  child 
did  not  thrive  until  placed  on  a  domestic  mixture. 

Why  should  a  food  which  so  nearly  approaches  breast-milk  in 
its  composition,  which  is  uniform  in  its  make-up,  sterile,  and 
easily  and  accurately  modified  to  meet  digestive  emergencies, — 
why  should  it  fail  when  put  to  a  clinical  test?  Starr  thinks 
that  it  is  due  to  the  destruction  of  the  natural  fat  emulsion 
by  the  use  of  the  separator.  In  some  way  the  digestibility 
of  the  proteids  is  diminished,  thus  giving  rise  to  malnutrition 
or  to  irritative  diarrhoea.  Starr  has  never  seen  an  infant 
below  the  age  of  ten  months  who  could  tolerate  a  laboratory 
mixture  containing  over  one  and  a  half  per  cent,  proteids, 
and  has  often  encountered  cases  where  at  the  age  of  two  months 
or  more  a  percentage  of  0.50  proteids  was  not  digested.  "  When 
unseparated  milk  is  the  basis  of  our  mixture,  and  we  have  a 
natural  emulsion  to  deal  with,  the  proteids  are  much  more 
easily  digested,  so  that  a  badly  nourished  child  of  ten  months, 
in  whom  Laboratory  Milk  percentage  cannot  be  forced  higher 


128  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

than  1.5  proteids,  will  easily  digest  and  grow  strong  upon  a 
domestic  mixture  containing  proteids  2.97  per  cent.,  sugar 
4.94  per  cent.,  and  fat  3.75  per  cent."  Of  course  the  same  care 
must  be  taken  in  home  modification  to  secure  pure,  clean  milk 
and  cream  from  healthy,  well-tended  cows.  Pasteurization 
can  be  carried  out  at  the  home,  and  accurate  measurements 
of  the  food  quantities  and  cleanliness  of  the  vessels  and  bottles 
can  be  obtained.  The  daily  variations  in  the  milk  and  cream 
Starr  considers  a  minor  detail  of  questionable  importance  when 
compared  with  the  destruction  by  the  separator  of  the  chemi- 
cal combinations  present  in  milk.  We  certainly  should  not 
sacrifice  everything  to  chemical  accuracy. 

He  does  not  wish  to  be  understood  as  condemning  Laboratory 
Milk  absolutely.  Its  introduction  has  greatly  advanced  sub- 
stitute infant  feeding  by  drawing  attention  to  the  importance 
of  cleanliness  and  accuracy  in  the  quantity  and  composition 
of  milk  formulae.  It  has  placed  the  whole  question  on  a 
higher  scientific  plane  than  had  ever  been  reached  before. 

Holt.183  The  following  principles  form  the  basis  of  all 
methods  for  the  scientific  feeding  of  infants : 

"  I.  Mother's  milk  is  not  only  the  best,  it  is  the  only  ideal 
infant  food. 

"  II.  Any  substitute  should  furnish  the  same  constituents, — 
namely,  fat,  sugar,  proteids,  salts,  and  water;  furthermore, 
they  should  be  in  about  the  same  proportions  as  they  exist  in 
woman's  milk. 

"  III.  As  nearly  as  possible  the  different  constituents  should 
resemble  those  of  mother's  milk  both  in  their  chemical  compo- 
sition and  in  their  behavior  to  the  digestive  fluids. 

"  IV.  These  conditions  are  fulfilled  only  by  fresh  milk  from 
some  other  animal. 

"  The  central  thought  of  the  American  or  percentage  system 
of  feeding  is  to  consider  the  different  elements  of  the  food 
separately  and  to  adapt  their  proportions  to  the  child's  diges- 
tion. ...  It  aims  to  discover  the  proper  proportion  of  fat, 


MODERN    METHODS   OF   INFANT   FEEDING.  129 

sugar,  and  proteids  and  the  best  methods  of  gradational  in- 
crease for  healthy  infants  with  normal  digestions,  and  also  to 
discover  for  those  with  abnormal  or  feeble  digestion  the  com- 
binations best  suited  to  the  individual  conditions." 

Since  one  element  of  the  milk  alone  may  be  at  fault,  it  is 
often  sufficient  to  reduce  its  proportion  without  reducing  the 
proportions  of  all  the  elements  or  entirely  giving  up  the  use 
of  milk. 

Fat. — The  average  amount  of  fat  which  a  healthy  infant 
can  digest  is  one  per  cent,  on  the  second  day,  two  per  cent, 
at  one  week,  increased  to  three  per  cent,  at  three  or  four  weeks 
and  to  four  per  cent,  at  four  or  five  months. 

Sugar. — It  is  seldom  necessary  to  reduce  the  sugar  per- 
centage'below  five  or  to  exceed  seven,  the  quantity  present  in 
mother's  milk.  As  the  sugar  in  milk  is  simply  lactose  in  solu- 
tion, it  is  only  necessary  to  calculate  the  amount  required  to 
bring  the  percentage  up  to  that  desired.  The  milk-sugar  must 
be  filtered  through  absorbent  cotton  if  it  contain  impurrties, 
and  dissolved  in  boiling  water ;  it  must  be  prepared  fresh  every 
day  in  summer  and  every  second  day  in  winter.  If  good  milk- 
sugar  cannot  be  obtained,  cane-sugar  may  be  substituted;  but 
little  more  than  half  the  quantity  is  needed  as  compared  with 
milk-sugar  on  account  of  its  greater  sweetness  and  greater 
liability  to  ferment  in  the  stomach.  In  exceptional  cases  cane- 
sugar  or  maltose  is  better  borne  than  lactose. 

Proteids. — The  proteids  give  the  most  trouble  to  the  infant's 
digestion.  In  the  first  few  days  their  proportion  should  be 
reduced  to  from  0.33  to  0.50  per  cent.  The  secret  of  success 
is  to  reduce  the  proteids  at  the  start  to  such  proportions  as 
the  infant  can  easily  digest,  then  gradually  to  increase  the 
quantity.  At  the  end  of  the  first  month  the  average  child  can 
take  one  per  cent.,  from  two  to  three  months  one  and  a  half 
per  cent.,  and  from  four  to  five  months  two  per  cent.  This 
reduction  in  proteids  is  effected  by  dilution  with  water.  Except 
to  start  with  too  high  proteids,  no  more  common  mistake  is 


130  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

made  than  to  continue  too  long  with  too  low  proteids.  Anae- 
mia, malnutrition,  and  not  infrequently  scurvy  result  from 
this  practice. 

Diluents. — Barley-,  rice-,  and  oatmeal-water  are  convenient 
forms  in  which  starch  may  be  added  to  the  food  of  infants 
who  are  old  enough  to  be  able  to  digest  it, — e.g.,  from  seven 
to  eight  months.  More  diluted,  they  may  be  used  to  allay  thirst 
when  the  stomach  is  irritable  and  all  forms  of  milk  must 
temporarily  be  withheld.  Eice-water  or  barley-water  is  usually 
preferable  when  there  is  diarrhoea,  and  oatmeal-water  when 
there  is  constipation.  It  is  questionable  whether  barley-water 
is  superior  to  plain  water  as  a  diluent;  in  some  cases  it  cer- 
tainly seems  to  be  useful. 

Salts. — Like  the  proteids,  inorganic  salts  are  in  excess  in 
cow's  milk,  and  in  nearly  the  same  proportion,  so  that  the 
dilution  of  the  one  causes  that  of  the  other. 

Reaction. — The  acidity  of  cow's  milk  may  be  overcome  by 
the  addition  of  either  lime-water  or  sodium  bicarbonate.  Of 
the  former,  one  ounce  is  enough  for  twenty  ounces  of  the  milk 
mixture;  of  the  latter,  one  grain  to  each  ounce  is  sufficient. 
For  very  young  infants  it  is  often  desirable  to  add  twice  as 
much  lime-water. 

Milk-Laboratory. — The  establishment  of  the  milk-labora- 
tory is  a  great  stride  in  advance  in  infant  feeding,  since  it 
becomes  possible  to  vary  any  one  of  the  constituents  of  the 
food  separately  until  the  combination  is  reached  which  is 
suited  to  the  infant's  digestion.  It  is  also  a  decided  advantage 
to  know  that  the  child  is  getting  exactly  what  has  been  ordered, 
and  not  to  have  to  put  up  with  the  ignorance  or  carelessness 
of  the  mother  or  nurse  who  otherwise  would  prepare  the  food. 
The  main  objection  to  Laboratory  Milk  has  been  its  expense. 
Holt  does  not  consider  that  there  is  any  difference  in  the 
digestibility  of  centrifugal  and  gravity  cream. 

The  following  table  represents  the  average  percentages  of 
proteids,  sugar,  and  fat  which  the  healthy  infant  can  take: 


MODERN    METHODS   OF   INFANT   FEEDING. 


131 


Fat, 

Age.  Per 

cent. 

Premature  infants  ....  1.0 

First  to  fourth  day 1.0 

Fifth  to  seventh  day.  . .  1.5 

Second  week 2.0 

Third  week 2.5 

Fourth  to  eighth  week.  3.0 

Third  month 3.0 

Fourth  month 3.5 

Fifth  month 3.5 

Sixth  to  tenth  month. .  4.0 

Eleventh  month 4.0 

Twelfth  month 4.0 

Thirteenth  month 4.0 


Sugar. 
Per 
cent. 

Proteids. 
Per 
cent. 

Amount  at 

each  feeding. 

Ounces. 

No.  of 
feedings  in 
24  hours. 

Interval 
by  day 
in  hours. 

4.0 

0.25 

H 

12- 

18 

1-1* 

5.0 

0.3 

l-i  j 

6- 

10 

2-4 

5.0 

0.5 

1-2 

10 

2 

6.0 

0.6 

2-2£ 

10 

2 

6.0 

0.8 

2-3* 

10 

2 

6.0 

1.0 

2£-4 

9 

2* 

6.0 

1.25 

3-5 

8 

2* 

7.0 

1.5 

3£-5£ 

7 

3 

7.0 

1.75 

4-6 

7 

3 

7.0 

2.0 

5-8 

6 

3 

5.0 

2.5 

6-9 

5 

4 

5.0 

3.0 

7-9 

5 

4 

4.5 

3.5 

7-10 

5 

4 

Home  Modification  of  Milk. 

Holt  considers  that  three  and  a  half  per  cent,  proteids  is 
more  nearly  the  correct  average  of  the  mixed  milk  of  a  herd 
than  four  per  cent.,  the  average  ordinarily  given.  The  follow- 
ing table,  based  on  analyses  by  Adriance  and  others,  represents 
pretty  accurately  the  composition  of  creams  of  different  den- 
sity: 


Per  cent. 

Fat 4.00 

Sugar 4. 50 

Proteids 3.50 

Salts 0.75 


II. 

Per  cent. 

ill. 

Per  cent. 

IV. 

Per  cent. 

v. 

Per  cent. 

8.00 

12.00 

16.00 

20.00 

4.35 

4.20 

4.05 

3.90 

3.40 

3.30 

3.20 

3.05 

0.70 

0.65 

0.60 

0.55 

Since  in  most  modifications  of  milk  the  fat  must  be  con- 
siderably higher  than  the  proteids,  it  may  be  introduced  by 
the  addition  of  cream  or  by  using  top  milk. 


132  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

A  series  of  experiments  (one  hundred  and  ten  analyses)  at 
the  Walker-Gordon  farm  have  shown  that  if  mixed  milk  be 
immediately  bottled  and  cooled,  after  four  hours  the  upper 
fourth  will  contain  nearly  all  the  fat,  which  will  rise  as  cream, 
and  the  upper  layers  will  have  nearly  the  same  percentage  of 
fat  whether  the  milk  has  stood  for  four  hours,  for  eight  hours, 
or  overnight. 


Upper  four  ounces. . 
Second  four  ounces  . 
Third  four  ounces  .  . 
Fourth  four  ounces  . 
Fifth  four  ounces . . . 


After  four  hours. 

After  eight  hours. 

Overnight. 

Per  cent,  of  fat. 

Per  cent,  of  fat. 

Per  cent,  of  fat. 

20.50 

21.25 

22.00 

6.00 

6.50 

6.50 

1.50 

1.40 

1.00 

1.20 

1.00 

0.30 

1.00 

1.00 

0.05 

Using  standard  milk  containing  four  per  cent,  fat,  we  can 
secure  approximately  the  following  results : 


Sixteen  ounces,  or  the  upper  half,  furnish  . 
Eleven  ounces,  or  the  upper  third,  furnish . 
Eight  ounces,  or  the  upper  fourth,  furnish. 
Six  ounces,  or  the  upper  fifth,  furnish 


Fat, 

Sugar. 

Proteids. 

Per  cent. 

Per  cent. 

Percent. 

7 

4.40 

3.40 

10 

4.30 

3.30 

13 

4.15 

3.25 

16 

4.05 

3.20 

If  the  milk  we  are  using  is  rich  in  fat  (five  per  cent,  or 
over),  from  two  to  three  ounces  more  should  be  removed  for 
each  formula;  if  it  is  poor  in  fat  (from  three  to  three  and 
a  half  per  cent.),  about  two  ounces  less  than  the  amount  speci- 
fied should  be  used. 

The  three  formulas  which  are  most  useful  are:  (1)  Those 
where  the  fat  is  three  times  the  proteids.  (2)  Those  where 
the  fat  is  twice  the  proteids.  (3)  Those  where  they  are  about 
equal. 


MODERN   METHODS   OF   INFANT   FEEDING.  133 

Series  A. — Eatio  of  fat  to  proteids,  three  to  one. 

Primary  formula  (ten  per  cent,  milk)  :  fat  ten  per  cent., 
sugar  4.30  per  cent.,  proteids  3.30  per  cent.  Obtained  (1) 
by  using  the  upper  one-third  of  bottled  milk,  or  (2)  by 
using  equal  parts  of  milk  (four  per  cent.)  and  cream  (six- 
teen per  cent.). 

Derived  Formula  giving  Quantities  for  Twenty-Ounce 
Mixtures. 

Milk-sugar one  ounce. 

Lime-water one  ounce. 

Boiled  water to  make  twenty  ounces. 


I.  With  one  ounce  of  ten  per  cent,  milk  .  .  . 

II.  With  two  ounces  of  ten  per  cent,  milk  . . 

III.  With  three  ounces  of  ten  per  cent.  milk. 

IV.  With  four  ounces  of  ten  per  cent.  milk.  . 
V.  With  five  ounces  of  ten  per  cent,  milk . . 

VI.  With  six  ounces  of  ten  per  cent,  milk  . . 

VII.  With  seven  ounces  of  ten  per  cent.  milk.     3.50         6.50  1.20 


To  make  twenty-five  ounces,  add  one-fourth  more  of  all  the 
ingredients;  to  make  thirty  ounces,  add  one-half  more. 

Series  B. — Eatio  of  fat  to  proteids,  two  to  one. 

Primary  formula  (seven  per  cent,  milk)  :  fat  seven  per 
cent.,  sugar  4.40  per  cent.,  proteids  3.40  per  cent.  Obtained 
(1)  by  using  the  upper  half  of  bottled  milk,  or  (2)  by  using 
three  parts  milk  (four  per  cent.)  and  one  part  cream  (sixteen 
per  cent.). 

Derived  formulae  giving  quantities  for  twenty-ounce  mix- 
tures.   Amount  of  milk-sugar,  lime-water,  and  water  as  above. 


Fat. 

Sugar. 

Proteids. 

er  cent. 

Per  cent. 

Per  cent. 

0.50 

5.20 

0.17 

1.00 

5.40 

0.33 

1.50 

5.60 

0.50 

2.00 

5.85 

0.66 

2.50 

6.05 

0.83 

3.00 

6.25 

1.00 

134  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

Fat.           Sugar.  Proteids. 

Per  ceut.    Per  cent.  Per  cent. 

I.    With  one  ounce  of  seven  per  cent.  milk. .    0.35        5.20  0.17 

II.    With  two  ounces  of  seven  per  cent.  milk.     0.70         5.40  0.35 

III.  With  three  ounces  of  seven  per  cent,  milk    1.05         5.60  0.52 

IV.  With  four  ounces  of  seven  per  cent.  milk.     1.40         5.80  0.70 
V.    With  five  ounces  of  seven  per  cent.  milk.     1.75        6.00  0.87 

VI.    With  six  ounces  of  seven  per  cent,  milk . .    2.10        6.20  1.05 

VII.    With  seven  ounces  of  seven  per  cent,  milk    2.45        6.45  1.22 

VIII.    With  eight  ounces  of  seven  per  cent,  milk    2.80        6.70  1.40 

IX.    With  nine  ounces  of  seven  per  cent.  milk.     3.15         6.90  1.55 

X.    With  ten  ounces  of  seven  per  cent,  milk . .     3.50         7.10  1.75 

XI.    With  eleven  ounces  of  seven  per  cent,  milk    3.85        7.30  1.92 

XII.    With  twelve  ounces  of  seven  per  cent,  milk    4.15        7.50  2.07 

Series  C. — Ratio  of  fat  to  proteids,  eight  to  seven. 

Primary  formula  (plain  milk)  :  fat  four  per  cent.,  sugar 
4.50  per  cent.,  proteids  3.50  per  cent. 

Derived  formulae  giving  quantities  for  twenty-ounce  mix- 
tures.   Amount  of  milk-sugar,  lime-water,  and  water  as  above. 

Fat.          Sugar.  Proteids. 

Per  cent.    Per  cent.  Per  cent. 

I.    With  two  ounces  of  four  per  cent,  milk  . .    0.40         5.40  0.35 

II.    With  four  ounces  of  four  per  cent.  milk. .    0.80         5.80  0.70 

III.  With  six  ounces  of  four  per  cent,  milk  . . .    1.20        6.20  1.05 

IV.  With  eight  ounces  of  four  per  cent,  milk  .    1.60        6.70  1.40 
V.    With  ten  ounces  of  four  per  cent.  milk. . .    2.00         7.10  1.75 

VI.    With  twelve  ounces  of  four  per  cent,  milk    2.40        7.60  2.10 

VII.    With  fourteen  ounces  of  four  per  cent,  milk    2.80        8.10  2.45 

VIII.    With  sixteen  ounces  of  four  per  cent,  milk    3.20         8.50  2.80 

When  the  formulae  contain  from  one-half  to  three-fourths 
milk,  three-fourths  of  an  ounce  of  milk-sugar  is  sufficient  for 
each  twenty  ounces;  if  more  milk  is  used,  add  only  half  an 
ounce  of  lactose. 


MODERN    METHODS   OF   INFANT   FEEDING.  135 

The  first  year  may  be  divided  into  three  feeding  periods: 
the  first,  from  birth  to  the  end  of  the  third  or  fourth  month; 
the  second,  from  this  time  to  the  end  of  the  tenth  month; 
the  third,  the  rest  of  the  first  year.  During  the  first  period 
the  best  results  are  obtained  when  the  fat  is  three  times  the 
proteids;  during  the  second  period,  when  the  fat  is  twice  the 
proteids;  during  the  third  period,  when  the  two  are  nearly 
equal. 

General  Rules  for  varying  Milk  Percentages. — No  sched- 
ule for  infant  feeding  can  be  followed  with  absolute  regularity, 
since  in  each  case  the  individual  factors  must  be  taken  into 
account,  such  as  the  age,  weight,  condition  of  the  digestive 
organs,  etc.  An  infant  that  at  four  months  weighs  as  much  as 
the  average  infant  at  eight  months  will  usually  be  able  to  take 
a  quantity  of  food  and  also  the  percentage  advised  for  the 
latter  age.  Again,  there  are  many  cases  in  which  the  per- 
centages of  the  milk  must  be  increased  more  slowly  than  the 
schedule,  but  the  same  gradational  steps  of  increase  may  ad- 
vantageously be  followed  with  all  cases. 

During  the  first  two  or  three  weeks  of  life  no  material  gain 
in  weight  is  to  be  expected  while  the  infant  is  taking  mix- 
tures with  very  low  percentages.  This  condition  may  be  con- 
sidered entirely  satisfactory,  provided  the  child  is  comfortable 
and  shows  no  signs  of  indigestion;  the  strength  of  the  food 
may  gradually  be  increased  with  the  demands  of  the  child's 
appetite,  and  gain  in  weight  will  usually  follow  after  a  short 
time.  "Nothing  is  easier  than  to  derange  the  organs  (of 
digestion)  during  the  first  weeks  by  too  high  percentages,  and 
such  disturbances,  even  though  they  appear  trivial,  often  con- 
tinue for  many  weeks." 

A  caution  is  necessary  against  changing  the  formulae  too 
frequently,  since  it  is  not  possible  to  determine  the  infant's 
ability  to  digest  a  certain  mixture  short  of  at  least  two  days. 

Special  Symptoms. — The  frequent  regurgitation  (often  one 
or  two  hours  after  feeding)  of  sour  curdled  milk  or  a  watery 


136  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

fluid  is  usually  an  indication  that  the  proportion  of  fat  is 
too  high.  The  first  indication  is  to  reduce  the  amount  of  fat; 
other  modifications  which  may  be  useful  are  to  give  double 
the  amount  of  lime-water  (ten  per  cent.)  or  to  reduce  the 
sugar  percentage.  It  is  important  that  the  food  be  taken 
slowly,  that  the  child  be  kept  perfectly  quiet  after  feeding, 
and  that  the  intervals  between  feedings  be  longer  than  in  the 
case  of  good  digestion. 

Constipation  during  the  first  weeks  of  life,  unless  associated 
with  manifest  discomfort  on  the  part  of  the  child,  should  be 
disregarded,  especially  if  the  odor  and  color  of  the  discharges 
are  nearly  normal.  It  is  a  mistake  to  increase  the  fat  per- 
centage rapidly,  since  in  a  few  days,  when  the  proportions 
of  the  proteids  and  the  fat  are  gradually  increased  according 
to  the  schedule,  this  form  of  constipation  will  pass  away. 
"  Anything  higher  than  three  per  cent,  of  fat  during  the  first 
four  or  five  weeks  almost  always  works  badly;  over  four  per 
cent,  at  any  time  during  the  first  year  can  seldom  be  long 
continued  without  disturbing  digestion."  If  constipation  per- 
sists with  these  percentages,  it  is  better  to  adopt  other  meas- 
ures for  its  relief  than  to  further  increase  the  fat.  "  The 
habitual  colic  of  early  infancy  is  almost  invariably  due  to  too 
high  proteids,  and  rarely  occurs  when  percentages  as  low  as 
those  above  advised  are  given." 

"  The  appearance  of  curds  in  the  stools  is  usually  associated 
with  colic  and  constipation;  it  is  commonly  due  to  too  high 
proteids  or  to  inability  to  digest  the  proteids  given,  even  though 
the  percentages  are  not  high."  Loose  green  or  yellowish-green 
stools  of  a  sour  odor  are  sometimes  caused  by  too  high  a  per- 
centage of  sugar,  but  more  often  by  an  excess  of  fat.  There 
are  usually  from  two  to  five  stools  a  day  resembling  thin 
scrambled  eggs.  The  small  yellowish  masses  are  often  mistaken 
for  curds.  Stools  such  as  those  described  are  often  seen  in 
nursing  infants  as  well  as  in  those  artificially  fed,  and  the 
condition  is  not  incompatible  with  steady  and  regular  gain  in 


MODERN    METHODS   OF   INFANT   FEEDING.  137 

weight.  After  it  has  persisted  any  length  of  time  mucus  is 
regularly  present  and  an  intractable  intestinal  catarrh  may 
be  produced.  Large  dry,  white,  or  gray  stools,  which  are  often 
smooth,  are  generally  due  to  an  excess  of  fat.  They  have 
usually  a  peculiarly  foul  odor  owing  to  the  presence  of  fatty 
acids,  and  may  be  distinguished  from  curds  by  their  solu- 
bility in  ether  and  by  their  burning  readily  with  the  odor  of 
butter. 

Feeding  of  Difficult  Cases. — These  cases  include  those 
infants  who  do  not  gain  in  weight  (or  whose  gain  is  irregular. 
— Editors)  and  who  habitually  suffer  from  indigestion.  The 
great  majority  result  from  previous  improper  feeding  or  equally 
improper  nursing.  "  These  cases  are  serious,  since  in  most  of 
them  nothing  can  be  accomplished  without  close  and  continuous 
personal  observation.  They  do  not  tend  to  right  themselves, 
and  the  infant's  life  is  often  sacrificed  as  the  result  of  bad 
management."  In  the  management  of  such  a  case  we  must 
not  only  ascertain  the  previous  methods  of  feeding,  but  also 
investigate  thoroughly  the  way  in  which  the  food  has  been 
prepared  and  administered  (the  condition  of  the  nipples  and 
bottles,  the  time  between  meals,  cleanliness,  etc.). 

Although  some  children  do  better  with  shorter  intervals  and 
smaller  quantities,  generally  speaking,  the  intervals  should  be 
longer  than  in  health.  It  is  seldom  wise  to  make  them  less 
than  three  hours  for  young  infants  or  less  than  four  hours 
for  those  who  have  passed  the  eighth  or  ninth  month.  When 
symptoms  make  a  reduction  in  the  food  necessary,  whether  in 
quantity  or  strength,  it  should  in  most  cases  be  radical  to 
produce  any  decided  effect.  On  the  other  hand,  in  increasing 
either  the  strength  or  the  quantity  of  the  food,  the  changes 
must  be  made  very  gradually,  lest  we  overtax  the  sensitive 
digestion. 

"In  troublesome  protracted  cases  it  is  better,  as  a  rule, 
to  go  to  the  opposite  extreme  from  that  which  has  previously 
been  tried ;  large  feedings  should  take  the  place  of  small  feed- 


138  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

ings,  long  intervals  of  short,  and  a  stronger  food  may  succeed 
one  which  is  very  dilute." 

An  infant  who  has  been  long  fed  on  farinaceous  foods  will 
probably  improve  when  these  are  stopped  entirely  and  suitable 
percentages  of  cow's  milk  are  given.  On  the  other  hand,  it 
may  be  necessary  temporarily  to  withdraw  milk  in  any  form. 
"  Such  a  course  is  often  better  than  wasting  time  in  juggling 
with  fractional  milk  percentages  when  one  or  two  intelligent 
trials  have  been  entirely  unsuccessful." 

In  modifying  milk  for  difficult  cases,  it  is  rarely  necessary 
to  reduce  the  sugar  below  four  per  cent.;  it  should  never  be 
given  above  seven  per  cent.  It  is  not  often  that  the  fat  can 
be  raised  above  three  per  cent,  in  cases  of  feeble  digestion, 
even  when  they  are  over  six  months  old.  For  younger  infants 
"  two  per  cent,  is  as  much  as  it  is  wise  to  give,  if  there  is  any 
disposition  to  vomiting  or  regurgitation.  Where  such  symp- 
toms are  prominent,  it  may  be  necessary  for  a  time  to  reduce 
the  fat  to  one  and  a  half  or  even  to  one  per  cent."  Infants 
suffering  from  marasmus  have  a  special  difficulty  in  digesting 
the  fats,  while  it  is  a  common  practice  to  give  them  in  large 
proportions. 

In  no  class  of  cases  is  it  more  important  to  begin  with  low 
percentages  of  proteids  than  in  those  with  naturally  feeble 
powers  of  digestion.  Disturbance  is  pretty  sure  to  result  if 
we  begin  by  administering  one  or  two  per  cent,  of  proteids 
to  a  very  young  infant.  On  the  other  hand,  if  we  begin  with 
0.33  or  0.50  per  cent,  proteids  and  gradually  increase,  there  is 
seldom  any  trouble. 

In  dealing  with  infants  whose  digestions  have  already  been 
upset,  "  it  is  usually  wise  to  begin  by  reducing  the  percentage 
of  the  disturbing  element — fat  or  proteids — to  a  point  where 
the  child's  most  obvious  symptoms  of  disturbance  disappear, 
and  then  gradually  but  very  slowly  to  increase,  but  to  go  no 
faster  than  the  child's  digestion  will  warrant,  regardless  of 
his  appetite."    It  is  impossible  to  feed  these  cases  like  healthy 


MODERN   METHODS   OF   INFANT   FEEDING.  139 

children  and  equally  impossible  to  tell  in  advance,  until  one 
lias  tried,  just  what  mixture  will  succeed. 

Holt  believes  that  in  some  cases  the  addition  of  the  cereal 
gruels  to  the  milk  is  "  of  material  assistance  in  the  digestion 
of  the  milk  proteids."  He  prefers  those  made  from  prepared 
flours  which  need  only  from  twenty  to  thirty  minutes'  cooking. 
The  strength  should  be  one  rounded  tablespoonful  to  a  pint 
of  water.  "  A  caution  should  be  given  against  using  too  large 
a  quantity  of  plain  or  even  dextrinized  gruels,  for  in  this  way 
the  flatulent  intestinal  indigestion  among  the  children  of  the 
poorer  classes  is  frequently  produced." 

In  some  cases  in  which  fat  and  proteids  are  very  difficult  of 
digestion,  owing  either  to  acute  or  chronic  gastro-intestinal  de- 
rangements, it  may  become  necessary  to  give  temporarily  a  food 
composed  almost  entirely  of  carbohydrates,  either  farinaceous 
or  malted  foods.  This  may  be  continued  for  from  a  few  days  to 
two  or  three  weeks,  according  to  the  severity  of  the  symptoms ; 
but  we  must  return  as  soon  as  possible  to  a  milk  diet,  beginning 
with  the  smallest  proportions  of  milk,  or  whey,  or  even  con- 
densed milk. 

For  difficult  cases  during  the  second  year,  milk  should  be 
the  principal  diet,  modified  as  for  healthy  infants  from  eight 
to  twelve  months  younger  than  the  patient  under  treatment. 
Peptonization  may  be  required  even  when  the  percentage  of 
casein  is  not  high.  The  daily  quantity  should  generally  be 
somewhat  larger  than  for  a  young  healthy  infant  taking  food 
of  the  same  strength.  The  interval  should  never  be  shorter 
than  three  hours,  and  in  many  cases  four  hours  are  to  be  pre- 
ferred. 

Eotch.119'  253  With  regard  to  the  problem  of  infant  feeding, 
Rotch  remarks  that  "  the  present  is  a  most  opportune  time  to 
raise  a  note  of  warning  against  allowing  our  enthusiasm  over 
any  one  especial  theory  to  warp  our  better  judgment.  There 
will  surely  be  a  reaction  which  will  relegate  to  its  proper  place 
every  theory  built  upon  single  factors  of  the  problem  before 


140  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

us,  and  which  is  actually  doing  harm  by  keeping  in  the  back- 
ground other  theories  which,  each  in  its,  own  sphere,  as  a 
significant  part  of  the  whole,  may  be  of  very  great  importance 
in  the  successful  solution  of  the  general  problem.  Our  scien- 
tific knowledge  and  clinical  investigations  have  not  yet  enabled 
us  to  follow  nature  exactly,  and  we  therefore  have  not  yet 
obtained  an  ideal  method  of  substitute  feeding.  We  must, 
nevertheless,  go  as  far  as  the  present  state  of  our  knowledge 
will  allow,  thus  gaining  a  little  ground  every  year,  and  we 
must  be  especially  careful  not  to  be  led  astray  by  the  ficti- 
tiously brilliant  results  which  are  reported  from  time  to  time 
in  favor  of  certain  foods." 

The  mortality  resulting  from  the  use  of  various  infant  foods 
always  remains  far  above  that  from  the  employment  of  human 
breast-milk. 

Kotch  is  convinced  that  the  choice  of  a  suitable  food  is  only 
part  of  the  problem  of  infant  feeding;  we  must  not  neglect 
to  "  investigate  and  carry  out  in  detail"  the  other  general 
factors,  neglect  of  which  has  had  much  to  do  with  our  failures 
with  substitute  feeding  in  the  past. 

"  Assuming,  then,  that  the  average  breast-milk  is  the  safest 
standard  for  us  to  copy,"  we  can  at  once  select  the  milk  of 
the  cow  as  the  most  available  substitute  from  which  to  ob- 
tain the  elements  of  our  artificial  food.  The  milk  of  other 
animals  may  approach  more  nearly  in  its  composition  to  that 
of  human  milk.  Apart  from  the  impossibility  of  obtaining 
it  in  sufficient  quantity,  however,  any  milk  will  require 
some  modification,  and  "it  is  as  easy  to  change  the  propor- 
tions of  the  different  constituents  to  a  great  degree  as  to  a 
small." 

The  general  factors  which  Eotch  considers  of  such  impor- 
tance in  the  preparation  of  an  infant  food  may  be  tabulated : 

(1)  A  pure  milk  obtained  from  healthy  cows,  under  proper 
hygienic  precautions  (see  Chapter  IX.). 

(2)  An  alkaline  reaction,  which  usually  requires  the  addition 


MODERN   METHODS   OF   INFANT   FEEDING.  HI 

of  an  alkali,  this  being  the  only  foreign  element  that  it  has 
been  found  necessary  to  employ. 

(3)  Thorough  dilution  of  the  food  with  water,  as  is  found 
in  human  milk.  Eotch  prefers  plain  water  to  decoctions  of 
starch. 

(4)  The  use  of  lactose  to  increase  the  sugar  content.  Cane- 
sugar,  which  some  authors  prefer,  seems  to  act  as  a  preserva- 
tive in  a  concentrated  form,  as  it  is  found  in  condensed  milk; 
but  when  it  is  diluted  it  ferments  very  readily.  Milk-sugar 
undergoes  no  direct  alcoholic  fermentation,  but  quickly  changes 
to  lactic  (possibly  acetic)  acid  in  the  presence  of  nitrogenous 
ferments,  while  cane-sugar  easily  undergoes  alcoholic  fermenta- 
tion, but  changes  to  lactic  acid  less  readily  than  milk-sugar; 
cane-sugar,  moreover,  takes  on  butyric  acid  fermentation  more 
readily  than  does  milk-sugar.  So  far  as  is  known,  cane-sugar 
is  merely  a  reserve  and  cannot  be  used  directly  for  nutrition, 
for  which  milk-sugar  may  possibly  have  a  direct  value.  Finally, 
reasoning  from  analogy,  we  should  say  that  as  milk-sugar  is 
the  only  form  of  sugar  found  in  the  milk  of  mammals,  it  is 
there  for  some  good  purpose,  and  that  it  is  needed  for  the 
accomplishment  of  some  process  which  takes  place  after  the 
food  has  been  swallowed. 

(5)  The  proper  modification  of  the  fat  and  proteids  of 
cow's  milk  to  suit  the  needs  of  the  individual  case. 

(6)  The  avoidance  of  starch.  As  woman's  milk  does  not 
under  any  circumstances  contain  starch,  and  as  the  function 
of  converting  starch  is  in  the  process  of  development  during 
the  first  ten  or  twelve  months  of  life,  and  should  therefore 
not  be  taxed,  Eotch  believes  that  starch  should  not  form  part 
of  the  infant's  food  in  the  early  months  of  life. 

(7)  The  greatest  care  to  secure  absolute  cleanliness  of  the 
nursing-bottles  and  nipples;  the  latter  should  be  renewed 
frequently. 

(8)  The  adoption  of  uniform  intervals  between  the  feed- 
ings. 


142  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

(9)  The  amount  of  food  to  be  given  at  each  feeding  must 
be  carefully  regulated  according  to  the  gastric  capacity.  Fre- 
quently this  does  not  correspond  with  the  weight  of  the  infant, 
yet  the  weight  is  undoubtedly  of  the  greatest  importance  in 
determining  the  proper  amount  of  food  to  be  given  during  the 
early  months  of  life.  At  this  time  it  is  especially  necessary 
to  avoid  stretching  an  organ  so  easily  distensible  as  is  the 
infant's  stomach,  so  that  it  is  wiser  to  give  too  little  rather 
than  too  much  food. 

The  following  table  is  based  on  measurements  of  a  large 
number  of  infants'  stomachs. 

General  Rules  for  Feeding  during  the  First  Year. 
Day  feedings  begin  at  six  a.m.  and  end  at  ten  p.m. 

Intervals         -^       -        No.  of       Amount        Total  in 

Age.  of  feeding's        nlght         at  each     twenty-four 

feeding.  g  *    feedings,     feeding.         hours. 

Hours.  Cc.  Cc. 

One  week , 2  10  1  30  300 

Two  weeks 2  10  1  45  450 

Four  weeks 2  9  1  75  675 

Six  weeks   2£  8  1  90  720 

Eight  weeks 2|  8  1  100  800 

Three  months 2}  7  0  120  840 

Four  months 2$  7  0  135  945 

Five  months 3  6  0  165  990 

Six  months 3  6  0  175  1035 

Seven  months 3  6  0  190  1140 

Eight  months 3  6  0  210  1260 

Nine  months 3  6  0  210  1260 

Ten  months 3  5  0  255  1275 

Eleven  months 3  5  0  265  1325 

Twelve  months 3  5  0  270  1350 

Ssnitkin,  in  a  series  of  careful  investigations  at  the  Chil- 
dren's Hospital  at  St.  Petersburg,  determined  the  amount  of 


MODERN   METHODS   OF   INFANT   FEEDING.  143 

food  required  during  the  first  months  of  life.  He  concluded 
that  "  the  greater  the  weight  the  greater  the  gastric  capacity." 
To  calculate  the  amount  needed  take  T^  of  the  initial  weight 
of  the  infant  and  add  one  gramme  to  each  day  of  life;  for 
example,  if  the  initial  weight  is  three  kilogrammes,  T^  of  this 
will  be  thirty  grammes.  At  fifteen  days,  therefore,  give  thirty 
plus  fifteen,  or  forty-five  grammes. 

Eotch  considers  that  it  is  best  to  secure  first  of  all  the  proper 
digestion  of  the  food,  even  should  there  be  no  gain  in  weight, 
and  then  to  increase  the  percentages  of  the  different  elements. 
Sometimes  marked  hunger  requires  a  sudden  increase  in  the 
quantity  of  food.  This  may  be  due  to  rapid  growth  of  the 
infant's  stomach,  which  in  some  cases  is  out  of  proportion 
to  the  age  and  size  of  the  child. 

Milk-Laboratories. 

The  long-felt  desire  that  the  subject  of  infant  feeding  should 
be  reduced  to  a  more  exact  system  has  led  Eotch  to  give  his 
professional  assistance  to  the  establishment  of  milk-laboratories, 
which  have  become  so  well  known.*  They  enable  the  physician 
to  prescribe  the  infant's  food  exactly  as  he  prescribes  its  medi- 
cine. In  this  way,  when  lacking  in  success,  he  can  be  sure 
that  it  is  the  fault  of  the  food  he  is  giving,  and  not  because 
the  food  has  varied  from  what  he  supposed  he  had  ordered. 
No  one  mixture  will  in  all  cases  prove  successful,  but  a  great 
variety  in  the  percentages  of  the  different  elements  of  the  milk 
will  be  needed  in  substitute  feeding  just  as  they  already  exist 
in  maternal  feeding.  This  explains  the  diversity  of  results 
obtained  in  the  past  with  the  same  food  by  different  practi- 
tioners. 

The  laboratory  should  be  situated  in  a  healthy  locality,  and 


*  The  first  milk-laboratory  for  the  exact  modification  of  milk  was 
opened  in  Boston  in  1891  under  the  name  of  the  Walker-Gordon 
Laboratory. 


144  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

every  aseptic  precaution  taken  to  avoid  the  presence  or  develop- 
ment of  pathogenic  germs.  The  milk-rooms  where  the  milk  is 
received  from  the  farm  should  be  cool,  free  from  dust,  and  iso- 
lated as  far  as  possible  from  the  other  parts  of  the  labora- 
tory. There  should  also  be  an  entirely  separate  room  in 
which  the  boxes  and  bottles  returned  by  the  consumer  can 
immediately  be  sterilized  in  an  apparatus  reserved  for  this 
purpose. 

The  modifying  materials  used  in  the  laboratory  should  be 
carefully  kept  in  glass  vessels,  at  a  temperature  of  about  4.4°  C. 
(40°  F.),  in  order  to  prevent  the  growth  of  bacteria.  This 
is  preferable  to  using  materials  in  which  the  bacteria  have 
been  destroyed  by  heat.  Separate  rooms  should  be  provided 
for  the  separation  of  milk  and  for  its  modification,  and  the 
office  of  the  laboratory  must  also  be  apart  from  the  working- 
rooms.  It  is  also  necessary  that  all  odors  be  carefully  excluded 
from  the  milk-rooms,  as  they  are  so  easily  absorbed  by  milk. 
Finally,  the  employees  must  be  of  sufficient  intelligence  to  take 
a  proper  amount  of  interest  in  their  work. 

As  a  result  of  the  special  care  observed  in  the  selection  and 
feeding  of  the  cattle  on  the  Walker-Gordon  farms,  Laboratory 
Milk  may  be  said  to  have  an  almost  uniform  percentage  of  its 
own  at  all  times  of  the  year. 

The  first  step  towards  its  modification  is  to  separate  it 
into  cream  and  skim  milk.  The  separating-room  has  an  as- 
phalt floor  and  walls  of  white  tile,  which  are  kept  mois- 
tened and  free  from  every  kind  of  dirt  and  dust.  The  air 
is  kept  constantly  pure  by  a  ventilator.  The  centrifugal  sepa- 
rator removes  practically  all  of  the  fat  from  the  milk  except 
a  small  fraction  (0.13  per  cent.).  It  accomplishes  two  very 
important  results :  first,  it  separates  from  the  cream  and  milk 
any  dirt  or  foreign  matter  present,  and  secondly,  the  resulting 
cream  has  an  almost  stable  percentage  of  fat  (sixteen  per 
cent.).    The  distilling  apparatus  is  also  kept  in  the  separating- 


MODERN   METHODS   OF   INFANT   FEEDING.  145 

In  Laboratory  Milk  the  percentage  of  fat,  proteids,  sugar, 
and  salts  is  not  apt  to  vary  appreciably,  but  the  percentage 
of  fat  in  the  milk  of  individual  cows  differs  from  day  to  day 
and  thus  slightly  affects  the  amount  of  fat  present  in  the 
milk  of  the  herd.  To  determine  the  fat  percentage  we  use 
the  Babcock  milk-tester.  In  this  apparatus  the  fat  of  the 
milk,  previously  acidulated,  is  completely  separated  by  cen- 
trif ugation  at  a  high  temperature.  This  gives  the  daily 
percentage  of  fat  in  the  whole  milk,  as  the  sample  has  been 
taken  from  the  mixed  milk  of  the  entire  herd.  Since  the 
exact  percentages  of  the  constituents  in  the  cream  and  sepa- 
rated milk  are  determined  each  day,  it  is  easy  to  calculate 
the  proportions  of  each  which  are  required  to  fill  a  given  for- 
mula. 

A  physician  can  write  for  an  exact  prescription  containing 
so  much  proteids,  sugar,  fat,  and  salts,  and  be  as  sure  of 
obtaining  it  as  he  is  of  any  medical  formula  which  is  filled 
at  a  pharmacy.  These  prescriptions  are  filled  by  "  modify- 
ing clerks,"  each  of  whom  has  at  hand  jars,  with  tightly 
fitting  covers,  containing  the  necessary  ingredients, — namely, 
cream,  separated  milk,  a  carefully  prepared  twenty  per  cent, 
lactose  solution,  freshly  made  lime-water,  and  for  older  infants 
preparations  of  oats,  barley,  and  wheat.  The  feeding-tubes 
or  bottles,  the  exact  size  and  number  of  which  are  specified  in 
the  prescription,  are  filled  by  the  clerks  according  to  the  re- 
quired formula,  stoppered  with  sterile  non-absorbent  cotton, 
placed  in  racks  or  baskets  designed  to  hold  the  number  that  is 
needed,  and  are  then  ready  to  be  sterilized.  The  rule  of 
absolute  cleanliness  is  carried  out  in  every  possible  detail, 
from  the  table  on  which  the  materials  are  combined  to  the 
dress  and  hands  of  the  clerks. 

The  sterilizer,  which  is  placed  in  the  separating-room,  is  so 
arranged  that  the  steam  which  passes  through  it  can  be  regu- 
lated so  as  to  produce  any  degree  of  heat  required  up  to 
100°  C.   (212°  F.).    After  the  food  has  been  sterilized  (as 

10 


146  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

a  rule,  from  twenty  to  thirty  minutes)  the  baskets  are  placed 
in  a  cooling  tank,  where  the  temperature  of  the  food  is  reduced 
to  13.3°  C.  (38°  F.).  They  are  then  quickly  delivered  to  the 
consumers. 

The  baskets  and  bottles,  when  returned,  are  taken  directly 
to  the  wash-room,  which  is  entirely  shut  off  from  the  rest  of 
the  laboratory,  as  before  mentioned.  Here  they  are  thoroughly 
sterilized  and  washed;  the  tags  and  stoppers  are  destroyed. 

The  prescription  blank  which  is  used  at  the  Walker-Gordon 
Laboratory,  to  be  filled  out  by  the  physician,  is  arranged  as 
follows : 

ifi  Per  cent. 

Fat Keaction 

Milk-sugar Number  of  feedings 


Proteids Amount  at  each  feeding. . . . 

Mineral  matter ....    Heated  for 

Lime-water Heated  at 

Special  directions.  Eemarks. 

For  whom  ordered.  Infant's  age 


Infant's  weight  . 


Signature. 
Date.  M.D. 

It  will  be  seen  that  the  above  blank  allows  the  physician 
to  prescribe  exactly  as  he  sees  fit  and  to  regulate  the  degree 
of  heat  employed  in  the  preparation  of  the  milk.  The  per- 
centage of  mineral  matter  requires,  as  a  rule,  no  modification 
other  than  that  produced  by  the  dilution.  If  a  slightly  alka- 
line reaction  be  desired,  the  amount  of  lime-water  can  be  left 
to  the  discretion  of  the  modifying  clerk  without  distinctly 
specifying  it. 

The  prescriptions,  when  received,  are  copied  into  a  book 
in  the  office  of  the  laboratory,  and  are  then  translated  into 
such  a  form  as  can  readily  be  understood  by  the  modifying 
clerk. 


MODERN    METHODS   OF   INFANT   FEEDING.  147 

The  following  table  shows  the  practical  limits  of  milk-modi- 
fication which  can  be  accomplished  at  the  laboratory. 

I.     Low  Fats. 

Per  cent.  Per  cent.  Per  cent.  Per  cent. 

Fat 0.03        0.04  0.08  0.12-0.16 

Sugar 2.00        3.00  4.00-5.00  6.00-7.00 

Proteids 0.75        1.00  2.00  3.00-4.00 

II.     Low  Sugars. 

Per  cent.  Per  cent.  Per  cent.  Per  cent. 

Sugar 0.87         1.40  2.12  3.50-4.30 

Fat 2.00  3.00  3.50  4.00 

Proteids 0.75        1.00  2.00  3.00-4.00 

III.     Low  Proteids. 

Per  cent.  Per  cent.  Per  cent.  Per  cent. 

Proteids 0.22  0.34  0.45  0.53 

Fat 2.00  3.00  4.00  4.50 

Sugar 2.00  3.00  4.00-5.00  6.00-7.00 

Home  Modification. 

When  it  is  impossible  to  obtain  Laboratory  Milk,  Eotch 
advocates  the  following  method  of  home  modification,  pre- 
supposing an  ordinary  degree  of  intelligence  on  the  part  of 
the  mother. 

The  necessary  implements  are  as  follows: 

(a)  A  sterilizer,  which  is  simply  a  tin  can  large  enough 
to  contain  the  required  number  of  nursing-bottles.  It  can 
be  heated  on  the  stove  or,  if  elevated  on  legs,  by  an  alcohol 
lamp.  The  top  is  perforated  for  the  introduction  of  a  ther- 
mometer, so  that  the  exact  temperature  of  its  contents  can  be 
ascertained  at  any  time.  The  tubes  in  which  the  milk  is 
sterilized  are  simply  the  ordinary  oblong  graduated  feeding- 
bottles,  so  constructed  as  to  possess  no  corners,  the  bottom 
being  rounded,  not  flat.  These  are  stoppered  with  non-absorb- 
ent cotton. 

(b)  A  metal  rack  for  holding  the  bottles,  which  can  be 


148  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

lowered  into  the  sterilizer;   the  latter  is  then  rilled  with  water 
to  the  level  of  the  milk  in  the  tubes. 

(c)  A  thick  "cozy"  is  also  to  be  provided,  as  well  as  (d) 
a  glass  graduate  holding  two  hundred  and  fifty  cubic  centi- 
metres (eight  and  one-third  ounces)  and  (e)  a  sugar  measure 
holding  13.5  grammes  (three  and  three-eighths  drachms)  of 
lactose.  Finally,  there  must  be  (/)  a  glass  siphon  or  tube 
bent  into  the  shape  of  the  letter  U,  for  the  removal  of  the 
milk  from  the  jar  without  disturbing  the  cream. 

The  mother  should  be  made  to  understand  the  importance 
of  obtaining  a  milk  of  good  quality  from  a  reliable  dealer. 

As  soon  as  the  milk  is  delivered,  the  jar  should  be  placed  in 
ice-water  (to  which  a  teaspoonful  of  salt  should  be  added  for 
each  quart  of  water)  and  left  for  six  hours,  care  being  taken 
not  to  allow  the  temperature  of  the  water  to  fall  below  35°  F. 
At  the  end  of  this  time  the  lower  twenty-four  ounces  of  the 
milk  in  the  jar  is  siphoned  off.  The  remaining  eight  ounces 
of  cream  will  contain  about  ten  per  cent,  of  fat.  With  the 
cream,  milk,  milk-sugar,  a  fresh  solution  of  lime-water,  and 
some  plain  boiled  water  various  modifications  can  be  made, 
for  which  Eotch  gives  a  number  of  tables.  If  the  actual 
percentages  of  the  fat  and  proteid  constituents  of  the  milk 
and  cream  be  known,  they  can  be  combined  according  to  some 
of  the  formulae  devised  by  Westcott,  Baner,  and  others  (see 
Chapter  XIII.). 

When  the  mixture  is  completed,  the  feeding-bottles  are  filled 
with  the  amount  to  be  used  at  each  feeding,  placed  in  the 
rack,  and  lowered  into  the  sterilizer,  which  is  rilled  with  water 
to  the  level  of  the  milk  in  the  bottles.  The  temperature  can 
then  be  raised  to  any  desired  point  short  of  213°  F.  (Eotch 
employs  171°  F.),  after  which  the  can  is  moved  to  the  side 
of  the  stove  and  covered  with  the  "  cozy/'  which  in  a  warm 
place  should  retain  the  heat,  keeping  the  temperature  between 
167°  and  170°  F.  for  half  an  hour.  The  milk  should  then 
be  placed  in  the  ice-chest  until  used.     If  we  wish  to  avoid 


MODERN   METHODS   OF   INFANT   FEEDING.  149 

coagulating  the  lactalbumin,  the  temperature  must  not  exceed 
155°  F. ;  this  will  kill  most  of  the  bacteria  in  milk.  If  the 
milk  is  to  be  carried  long  distances,  fractional  sterilization 
may  be  employed  to  destroy  the  spores  of  the  bacteria. 

Regarding  the  question  whether  the  fat  emulsion  of  milk 
which  is  used  for  modification  is  interfered  with  or  destroyed 
by  centrifugation,  Rotch  has  found  by  microscopic  examination 
that  the  emulsion  of  one  of  his  mixtures  corresponds  almost 
exactly  with  that  of  the  human  milk  which  it  was  made  to 
represent.  So  far  as  the  emulsion  is  concerned,  no  injury  is 
done  by  separating  the  elements  of  milk  and  then  recombining 
them. 

For  a  healthy  infant  born  at  term,  of  normal  weight  and 
development,  Rotch  regulates  the  quantity  of  food  and  time 
of  feeding  according  to  the  table  (page  142).  During  the 
first  twenty-four  to  thirty-six  hours  he  gives  only  small  quan- 
tities of  a  five  per  cent,  solution  of  lactose.  During  the  first 
week  he  gives  a  mixture  containing:  fat  two  per  cent.,  sugar 
five  per  cent.,  proteids  from  0.25  to  0.75  per  cent.  This  must 
have  a  slightly  alkaline  reaction  and  must  be  pasteurized  at 
75°  C.  (167°  P.). 

Fat.  Sugar.  Proteids. 

Per  cent.        Per  cent.        Per  cent. 

Second  week 2.5  6.00  1.00 

Third  week 3.00  6.00  1.00 

Four  to  six  weeks 3.50  6.50  1.00 

Six  to  eight  weeks 3.50  6.50  1.50 

Two  to  four  months 4.00  7.00  1.50 

Four  to  eight  months 4.00  7.00  2.00 

Eight  to  nine  months 4.00  7.00  2.50 

Nine  to  ten  months 4.00  7.00  3.00 

Ten  to  ten  and  a  half  months 4.00  5.00  3.25 

Ten  and  a  half  to  eleven  months 4.00  4.50  3.50 

Eleven  to  eleven  and  a  half  months Unmodified  cow's  milk 


150  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

At  about  the  tenth  or  eleventh  month  Kotch  usually  begins 
to  give  one  and  then  two  meals  daily  of  oat  jelly  and  plain 
milk,  pasteurized  at  68°  C,  equal  parts,  with  a  pinch  of 
salt  added  to  suit  the  infant's  taste.  Barley  or  wheat  may 
also  be  used.  In  the  twelfth  month  he  accustoms  the  infant 
to  taking  bread  (one  day  old)  and  to  eat-  with  a  spoon,  so 
that  at  one  year  of  age  it  takes  bread  and  milk  for  breakfast 
and  supper  and  oat  jelly  and  milk  for  the  three  middle  meals. 

W.  P.  Northrup  221  dwells  on  the  importance  of  "  clean" 
milk  which  is  moderately  free  not  only  from  bacterial  con- 
tamination, but  also  from  the  products  of  their  activities, — 
the  toxins.  The  formation  of  the  latter  can  be  prevented  by 
the  immediate  cooling  of  the  milk,  after  it  is  drawn,  to  40°  F., 
at  which  temperature  most  bacteria  cannot  grow. 

In  Northrup's  experience  with  centrifugal  cream,  "there 
has  never  arisen  any  accident  or  incident  to  raise  objection  to 
it."  Moreover,  its  all-important  freshness  is  an  argument  in 
its  favor  which  it  is  difficult  to  overturn.  He  would  limit  the 
use  of  home  modifications  to  those  infants  who  are  already  well 
started  and  thriving  and  to  those  who  are  not  to  be  consid- 
ered as  delicate  or  in  a  critical  state.  u  For  really  difficult 
cases  (critical  cases),  in  which  there  is  risk  in  trying  things, 
in  which  it  is  necessary  to  find  the  right  feeding  at  once,  and 
in  which  the  condition  of  the  child  is  such  that  it  is  impor- 
tant not  to  risk  any  time,  he  has  no  hesitancy  in  saying  that 
there  is  no  feeding  so  reliable  and  so  good  as  the  modified 
milk."  The  only  objection  to  the  use  of  Laboratory  Milk  is 
its  expense. 

Northrup  also  insists  that  the  physician  should  have  a  proper 
knowledge  of  what  the  infant  requires  at  different  periods  of 
its  life  before  he  attempts  to  prescribe  this  or  that  formula. 

The  three  most  important  formulae  to  remember  are:  (1) 
Feeding  for  the  new-born  (proper  for  the  majority)  :  fat 
two  per  cent.,  sugar  five  per  cent.,  proteids  0.75  per  cent. 
(2)   "Low  average  breast-milk:"    fat  three  per  cent.,  sugar 


MODERN  METHODS   OF   INFANT   FEEDING.  151 

six  per  cent.,  proteids  one  per  cent.  (3)  "High  average 
breast-milk:"  fat  four  per  cent.,  sugar  seven  per  cent.,  pro- 
teids two  per  cent.  These  modifications  should  be  changed 
gradually  and  frequently,  by  small  fractions,  from  one  to 
another.  From  eight  months  to  one  year  the  proportions  should 
be  made  to  approximate  cow's  milk.  The  diet  should  be  all 
milk  for  the  first  year  and  mostly  milk  for  the  second  year. 

Koplik  79  divides  the  cases  under  his  observation  in  his 
dispensary  service  in  New  York  City  into  two  classes:  (a) 
those  who  were  fed  from  birth  on  modified  cow's  milk,  and 
(b)  those  who  were  given  the  breast  in  addition  to  cow's  milk. 
All  were  under  nine  months  of  age.  The  milk  was  sterilized 
at  from  90°  to  92°  C.  and  rapidly  cooled.  The  same  mixture 
was  given  to  all  cases.  It  was  composed  of  equal  parts  of 
cow's  milk  and  distilled  water,  with  six  per  cent,  of  crystal- 
lized milk-sugar, — the  so-called  Heubner-Hoffmann  Mixture. 
Children  under  three  months  received  ninety  cubic  centi- 
metres; older  children  were  given  one  ounce  (thirty  cubic 
centimetres)  more  for  each  month  of  their  age  till  eight  ounces 
(two  hundred  and  forty  cubic  centimetres)  were  reached,  when 
whole  milk  was  used.  Each  child  was  given  from  seven  to 
eight  bottles  a  day.  The  mothers  were  told  not  to  give  more 
than  one  and  a  half  ounces  at  a  time  to  babies  under  one 
month.     Systematic  weighings  were  carried  out. 

The  Heubner-Hoffmann  Mixture  contains:  water  90.57  per 
cent.,  proteids  1.78  per  cent.,  fat  1.85  per  cent.,  sugar  5.44 
per  cent.,  and  ash  0.36  per  cent. 

During  the  last  five  years  this  mixture  proved  satisfactory 
in  the  majority  of  cases.  In  a  few  cases  the  deficiency  in 
fat  was  made  up  as  follows :  sixteen  per  cent,  cream  was  added 
to  each  one  hundred  parts  of  the  Heubner-Hoffmann  Mixture, 
so  as  to  make  the  fat  content  four  per  cent.  We  know  that 
relatively  larger  quantities  of  cow's  milk  than  of  human  milk 
are  required  for  the  healthy  nutrition  of  infants;  but  there 
is  no  excessive  consumption,  even  when  quantities  are  taken 


152  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

which  are  greater  than  the  known  capacity  of  the  stomach 
(see  Camerer's  monograph,  Vienna,  1898).  The  best  results 
in  feeding  sickly  infants  were  obtained  with  Biedert's  minimal 
amounts. 

Class  A. — In  thirty  cases  Koplik  found  an  increase  in 
weight:  from  first  to  second  month,  thirty-two  grammes; 
second  to  third  month,  17.4  grammes;  third  to  fourth  month, 
23.6  grammes;  fourth  to  fifth  month,  eighteen  grammes; 
fifth  to  sixth  month,  14.2  grammes;  sixth  to  seventh  month, 
11.8  grammes;  seventh  to  eighth  month,  15.6  grammes;  eighth 
to  ninth  month,  15.1  grammes.  These  were  all  dispensary 
cases  from  the  lowest  classes,  whose  hygienic  surroundings  were 
most  unfavorable,  and  where  the  increase  in  weight  was  liable 
to  be  interfered  with  by  frequent  attacks  of  diarrhoea  and  other 


Class  B. — Infants  who  are  given  the  breast  in  addition  to 
the  bottle  undoubtedly  have  less  tendency  to  diarrhoea  and 
digestive  disturbances.  The  average  weight  and  the  daily 
increase  in  weight  are  greater  by  far  than  in  those  cases 
which  are  fed  on  the  bottle  alone.  The  daily  gain  was  greatest 
from  the  eighth  to  the  twelfth  and  the  twelfth  to  the  six- 
teenth week,  at  a  period  when  artificially  fed  children  have 
the  greatest  difficulty  in  maintaining  their  weight.  If  we  take 
thirteen  cases  in  which  the  babies  were  given  the  breast  and 
the  bottle  alternately,  we  note  the  following  gain  in  weight: 

8-12      12-16      16-20      20-24      24-28     28-32     32-36  week 
30         24.8  12  19.5        13.7         9.2         11.2  per  cent. 

Koplik  ascribes  the  irregularity  in  the  gain  to  the  tendency 
of  mothers  to  overfeed  their  children,  thus  leading  to  dys- 
pepsia and  temporary  losses.  Nevertheless,  the  gain  compared 
favorably  with  that  given  by  Camerer  in  his  table  estimated 
from  weighings  of  fifty-nine  breast-fed  infants. 

Biedert,  Meigs,  and  Eotch  have  devised  methods  by  which 
we  can  imitate  the  natural  food  of  the  infant.     Of  these  the 


MODERN   METHODS   OF   INFANT   FEEDING.  153 

Meigs  Mixture  is  unquestionably  the  best  milk-modification 
that  we  have  at  present.  It  is  a  mistake  to  think  that  all  we 
have  to  do  is  to  recombine  the  elements  of  milk  in  the  pro- 
portions present  in  mother's  milk.  Even  with  the  method 
of  Rotch,  which  allows  all  possible  variations  of  the  proteids, 
fat,  and  sugar  percentages,  there  are  a  certain  number  of 
infants  who  will  not  thrive  on  any  mixture  we  can  devise. 
These  are  the  cases  in  which  atrophy  gradually  develops, 
and  include  those  children  who  cannot  digest  milk  in  any 
form. 

While  some  atrophic  infants  do  not  thrive  on  a  fat  per- 
centage similar  to  that  of  mother's  milk,  in  others  'the  pres- 
ence of  the  fat  seems  to  favor  digestion  of  the  casein.  This 
simply  serves  to  show  how  complicated  the  problem  of  infant 
feeding  really  is.  When  we  consider  that  in  our  great  cities 
the  majority  of  mothers  have  to  depend  on  some  form  of  home 
modification,  the  best  of  which  are  those  formulated  by  Bie- 
dert,  Meigs,  and  Heubner,  we  see  that  it  is  not  so  much  the 
difference  between  1.2  and  one  and  a  half  or  two  per  cent, 
proteids  which  decides  the  child's  destiny  as  something  in- 
herent in  the  milk  itself,  in  that  we  have  to  do  with  casein 
which  is  very  indigestible,  especially  in  the  raw  state. 

Joseph  C.  Winters.235  An  artificial  food  must  contain 
nothing  that  is  not  found  in  human  milk ;  it  must  be  of  animal 
origin  and  it  must  be  fresh.  In  metropolitan  cities,  where 
the  milk  reaches  the  consumer  sixteen  hours  or  more  after 
milking,  the  proportions  of  the  ingredients  in  the  top  milk 
will  be  fairly  constant.  Analyses  made  by  Adriance  of  good 
milk  as  delivered  in  New  York  City  show  that  the  upper 
ounce  from  a  quart  of  it  will  contain:  fat  23.8  per  cent., 
sugar  3.90  per  cent.,  proteids  2.90  per  cent.;  the  upper  four 
ounces  will  contain:  fat  21.8  per  cent.,  sugar  four  per  cent., 
proteids  three  per  cent. ;  and  the  upper  eight  ounces  will 
contain:  fat  seventeen  per  cent.,  sugar  4.3  per  cent.,  proteids 
3.1  per  cent.     Winters  advises  for  the  early  days  of  infancy 


154  THE   ARTIFICIAL  FEEDING   OF   INFANTS. 

no  more  than  0.25  per  cent,  proteids  and  no  less  than  two 
per  cent.  fat.  Infants  so  fed  do  not  lose  weight  in  the  first 
week  of  life  as  they  do  under  other  conditions.  An  infant 
from  three  to  four  months  old  will  not,  as  a  rule,  digest  more 
than  one  per  cent,  of  proteids  in  hot  weather.  At  this  time 
the  proportion  of  lime-water  should  be  increased  to  one-fourth 
of  the  total  quantity  used,  and  the  strength  of  the  food  should 
be  increased  very  gradually.  Winters  has  seen  scurvy  follow 
the  use  of  pasteurized  milk,  with  rapid  recovery  on  the  use  of 
the  same  food  raw.  He  prefers,  whenever  possible,  to  employ 
milk  which  has  not  been  heated. 

Thompson  S.  Westcott.254  This  author  believes  with  Rotch 
that  milk-modifications  should  be  prescribed  in  formulae  ex- 
pressing the  percentage  composition  of  the  different  ingredients. 
For  this  purpose  whole  milk  and  creams  of  varying  strengths 
are  combined  according  to  mathematical  formulae.  He  also 
gives  a  table  showing  the  varying  percentages  of  fat  and  pro- 
teids that  can  be  obtained  by  mixing  whey  with  cream  of 
various  fat  percentages.  In  these  estimations  the  amount  of 
proteids  is  calculated  according  to  Konig's  analyses,  which  give 
2.88  per  cent,  casein  and  0.53  per  cent,  lactalbumin  in  cow's 
milk;  the  whey-proteids  are  estimated  to  equal  0.86  per  cent. 
(see  Chapter  XIII.). 

Westcott  emphasizes  the  importance  of  maintaining  the  di- 
gestive equilibrium.  For  this  purpose  clinical  experience  has 
taught  him  that  liberal  amounts  of  milk  and  cream  are  needed. 
In  mixtures  containing  from  thirty  to  thirty-two  ounces,  for 
instance,  the  quantity  of  milk  and  cream  must  reach  from 
twelve  to  thirteen  ounces  before  satisfactory  growth  and  nutri- 
tion can  be  expected.  Dilutions  weaker  than  this  must  be 
considered  underfeeding.  Both  upon  theoretical  and  clinical 
grounds,  a  percentage  of  proteids  below  1.50  must  be  con- 
sidered subnormal  for  any  but  the  youngest  infants;  there- 
fore, when  low  feeding  must  be  maintained  for  a  considerable 
time,  this  percentage  should  be  kept  constantly  in  mind  as 


MODERN   METHODS   OF   INFANT   FEEDING.  155 

the  index  of  concentration  which  it  is  desirable  to  reach  as 
soon  as  the  strength  of  the  infant's  digestion  will  permit. 

Westcott  advises  as  a  good  working  rule  to  make  the  fat 
percentage  about  three  when  the  proteid  percentage  is  one,  and 
gradually  to  increase  it  to  four,  while  the  proteid  percentage 
is  increased  to  two.  Exceptionally  the  fat  percentage  must 
be  reduced  below  three  for  delicate  infants  or  those  of  very 
tender  age.     For  the  purposes  of  modification : 


Fat.  Proteids.  Sugar.  Salts. 

Per  cent.  Per  cent.  Per  cent.  Per  cent. 

Whole  milk  is  calculated  to  consist  of .. .  4.00  4.00  4.40  0.70 
Twelve  per  cent,  cream  is  calculated  to 

consist  of 12.00       3.80  4.20  0.64 

Sixteen  per  cent,  cream  is  calculated  to 

consist  of 16.00       3.60  4.00  0.60 

Twenty  per  cent,  cream  is  calculated  to 

consist  of 20.00       3.20  3.80  0.55 


When  it  is  necessary  to  reduce  the  proteids  below  one  per 
cent,  to  establish  digestive  equilibrium,  the  use  of  the  whey- 
proteids  will  enable  the  infant  to  appropriate  a  larger  propor- 
tion of  the  more  assimilable  soluble  albuminoids  and  perhaps 
a  higher  percentage  of  total  proteids  than  any  other  plan  of 
feeding.  For  this  purpose,  in  preparing  the  whey,  the  curd, 
after  forming,  should  be  disturbed  as  little  as  possible,  the 
whey  being  allowed  to  drain  off  entirely  by  gravity.  The 
object  of  this  is  to  obtain  as  low  a  percentage  of  fat  as  pos- 
sible, since  the  mixture  will  now  become  essentially  a  cream 
dilution  and  nearly  all  the  fat  will  be  derived  from  the  cream. 

In  a  general  way  it  may  be  said  that  in  normal  cases  a  pro- 
teid percentage  of  two  should  not  be  reached  before  the  fifth 
or  sixth  month.  In  infants  with  chronic  digestive  disturbances 
it  may  be  several  months  later  before  so  high  a  percentage 
can  be  attained,  and  in  cases  of  delicate  digestion  it  may  not 


J  56  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

be  possible  to  increase  the  percentage  above  two  until  near  the 
end  of  the  first  year. 

Since  human  milk  contains  from  6.5  to  seven  per  cent,  lac- 
tose, a  corresponding  percentage  of  sugar  may  be  given  in 
the  mixture,  except  in  the  earliest  days  of  life,  when  a  per- 
centage of  4.5,  five,  or  5.5  would  be  more  suitable.  Crystalline 
milk-sugar  is  to  be  preferred  to  the  ordinary  powdered  sugar, 
which  can  readily  be  adulterated.  It  is  preferable  to  add  the 
necessary  weight  of  sugar  in  dry  form  rather  than  to  use  a 
watery  solution  of  definite  percentage  strength. 

In  cases  of  weak  gastric  or  intestinal  digestion  in  which 
only  very  low  percentages  of  proteids  can  be  assimilated,  de- 
cided advantage  is  often  gained  by  partial  predigestion  of  the 
milk  mixture.  In  this  way,  too,  higher  percentages  of  proteids 
can  be  given  than  is  possible  with  simple  dilutions.  The  author 
prefers  to  use  peptogenic  milk-powder  for  this  purpose.  Since 
this  consists  largely  of  milk-sugar,  the  bulk  of  the  powder  must 
be  deducted  from  the  quantity  of  milk-sugar  added  to  bring 
the  mixture  to  the  desired  percentage.  The  author  has  never 
observed  the  often-described  ill  effects  of  a  partially  peptonized 
diet,  although  this  mode  of  preparation  has  been  employed  in 
many  cases  that  demanded  it  for  from  three  to  six  months  or 
even  longer. 

It  is  usually  best  to  discontinue  partial  predigestion  slowly, 
first  gradually  reducing  the  time  of  action  to  three  or  four 
minutes,  and  then  decreasing  the  quantity  of  powder  to  a  third 
or  fourth  of  the  amount  originally  used,  after  which  it  may 
be  omitted. 

For  clinical  purposes  Woodward's  method  of  estimating  the 
proteids  in  breast-milk  and  the  Leffmann-Beam  method  for 
the  estimation  of  fat  are  recommended  (see  Appendix). 

Franklin  W.  White  and  Maynard  Ladd  203  have  recently 
called  the  attention  of  the  profession  to  the  subject  of  whey- 
cream  modifications  in  infant  feeding.  They  found,  on  re- 
ferring to  Bulletin  28  of  the  United  States  Department  of 


MODERN   METHODS   OF   INFANT   FEEDING.  157 

Agriculture,  that  a  large  number  of  specimens  of  whey,  as 
purchased,  yielded  one  per  cent,  of  whey-proteids.  Konig's 
analysis  of  whey,  accepted  by  Westcott,  allowed  0.86  per  cent, 
for  whey-proteids,  and  Westcott's  formulas  were  based  on  this 
figure.  The  result  of  six  analyses  by  the  authors  confirmed 
the  presence  of  one  per  cent,  of  proteids  in  whey.  Several 
analyses  of  the  total  proteids  in  whole  cow's  milk  gave  3.84 
per  cent. ;  of  this,  the  average  amount  of  whey-proteids  was 
0.90  per  cent.,  or  approximately  one-quarter  of  the  total  pro- 
teids; the  average  amount  of  caseinogen  was  2.94  per  cent., 
or  approximately  three-quarters  of  the  total  proteids.  They 
found  that  the  best  temperature  for  destroying  the  rennet 
enzyme  in  whey  was  65°  C.  (149°  F.).  Temperatures  of 
69.3°  C.  and  higher  coagulate  the  whey-proteids.  The  rennet 
must  be  destroyed  before  mixing  the  whey  with  the  cream, 
in  order  to  prevent  the  coagulation  of  the  cream  by  the  enzyme. 

By  the  use  of  thirty-two  per  cent,  cream,  fat-free  milk,  and 
a  very  concentrated  solution  of  milk-sugar  they  were  able  to 
obtain  whey-cream  mixtures  with  a  maximum  of  0.90  per 
cent,  of  whey-proteids  in  combination  with  percentages  of 
caseinogen  varying  from  0.25  to  one,  giving  total  proteids  of 
from  1.15  to  1.90  per  cent. 

The  emulsions  of  fat  in  whey,  barley-water,  gravity  cream, 
and  centrifugal  cream  mixtures  were  the  same  both  in  their 
macroscopic  and  microscopic  appearances.  The  combination 
of  heat  and  jolting  during  transportation,  such  as  sometimes 
occurs  in  hot  weather,  partially  destroys  the  emulsion  in  all 
forms  of  modified  milk,  but  this  disturbance  can  be  prevented 
by  the  simple  precaution  of  keeping  the  milk  cool  during  de- 
livery. 

Whey-cream  mixtures  yield  a  much  finer,  less  bulky,  and 
more  digestible  coagulum  than  plain  modified  mixtures  with 
the  same  total  proteids;  the  coagulum  is  equalled  in  fineness 
only  by  that  of  barley  mixtures.  The  coagulum  yielded  by 
gravity  cream  mixtures  and  centrifugal  cream  mixtures  is  the 


158  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

same  in  character.  The  density  of  the  coagulum  is  not  affected 
by  a  variation  of  five  per  cent,  in  the  fat  content  of  the  cream. 
Experiments  on  animals  confirmed  the  results  obtained  in  the 
test-tubes. 

Charles  W.  Town-send  145  emphasizes  these  practical  points 
in  infant  feeding:  that  the  child  is  not  a  machine,  that  chil- 
dren vary  greatly  in  their  digestive  powers,  and  that  they  will 
not  always  do  what  is  expected  of  them.  Even  with  the  most 
patient  and  intelligent  changing  of  the  formulae  to  suit  the 
varying  needs  of  the  case,  laboratory  modifications  will  not 
always  agree,  "  though  often  of  the  greatest  service."  He 
thinks  that  a  possible  explanation  lies  in  the  fact  that  the 
cream  separated  by  centrifugation  recombines  with  milk, 
water,  and  lactose  in  varying  proportions,  and  is  then  churned 
up  by  being  carted  around  on  the  delivery  wagon  (see  May- 
nard  Ladd  and  White).  He  does  not  insist  on  pasteurization 
if  the  milk  be:  (1)  fresh,  (2)  obtained  from  cows  which  are 
found  to  be  free  from  tuberculosis  by  the  tuberculin  test,  and 
(3)  in  no  danger  of  contamination  by  the  germs  of  typhoid 
fever  or  other  infectious  diseases.  If  there  is  doubt  as  to  these 
three  particulars,  it  is  better  to  pasteurize  at  156°  F.  for 
twenty  minutes. 

For  home  modification  he  recommends  the  use  of  top  milk 
(upper  fourth)  which  contains  four  per  cent,  proteids  and 
from  ten  to  eleven  per  cent,  fat  after  standing  from  six  to 
eight  hours.  His  rule  is :  each  ounce  of  ten  per  cent,  cream 
in  a  twenty-ounce  mixture  represents  .50  per  cent,  fat,  .20 
per  cent,  proteids,  and  .20  per  cent,  sugar.  Each  even  table- 
spoonful  of  sugar  of  milk  represents  two  per  cent.  The  dilu- 
tions are  made  with  lime-water  and  boiled  water.  Skimmed 
milk  may  be  employed  when  it  is  desirable  to  increase  the 
percentage  of  proteids.  When  using  mixtures  low  in  proteids, 
as  in  entero-colitis,  the  addition  of  white  of  egg  is  useful. 

H.  Dwight  Chapin  25»  201  has  recently  recalled  the  atten- 
tion of  the  profession  to  the  use   of  top-milk  mixtures  in 


MODERN    METHODS   OF   INFANT   FEEDING.  159 

infant  feeding,  and  this  subject  will  be  discussed  in  Chap- 
ter XIII.  He  is  also  a  prominent  advocate  of  the  use  of 
decoctions  of  the  cereals  in  infant  feeding.247  "The  claim 
that  cereal  waters  have  no  more  effect  on  the  curd  of  cow's 
milk  than  plain  water  has  been  abandoned,  as  it  was  based 
on  the  precipitation  of  casein  with  dilute  acids  and  not  upon 
its  coagulation  with  rennet,  which  is  what  takes  place  in  the 
infant's  stomach.  ...  To  break  up  the  curd  of  cow's  milk 
and  furnish  a  small  quantity  of  easily  absorbable  food,  cereal 
gruels,  in  which  the  starch  has  been  converted  into  dextrin 
and  maltose,  are  the  most  practicable  and  desirable  agents. 
It  is  now  admitted  that  cereals  give  the  finest  curd  of  any 
diluent,  but  it  is  claimed  that  the  effect  of  the  cereal  is  lost 
when  the  starch  is  digested,  especially  if  the  digestive  ferment 
is  active.  How  much  effect  a  digested  gruel  has  on  the  curd- 
ling of  milk  depends  on  the  strength  of  the  gruel  and  the  dilu- 
tion of  the  milk.  The  very  best  effect,  so  far  as  the  digestive 
effort  is  concerned,  is  obtained  when  the  starch  is  completely 
gotten  into  soluble  forms,  so  that  the  particles  of  proteids 
and  cellulose  of  the  cereals  are  free."  Experiments  were  made 
by  adding  rennet  and  0.15  per  cent,  hydrochloric  acid  to 
(a)  raw  milk  diluted  equally  with  water,  (b)  the  same  diluted 
equally  with  one  and  a  half  per  cent,  starch  jelly,  and  (c) 
the  same  diluted  equally  with  dextrinized  gruel.  In  b  and 
c  the  curds  were  smaller  and  more  flocculent  than  in  a;  in  & 
the  curds  were  coated  with  starch,  but  in  c  they  were  thor- 
oughly exposed  to  the  action  of  the  gastric  juice. 

"  It  is  not  necessary  to  use  a  gruel  stronger  than  one  heap- 
ing tablespoonful  of  flour  to  the  pint  for  any  dilution  of  milk. 
Wheat,  oatmeal,  or  barley  may  be  used.  Besides  acting  as 
mechanical  attenuants,  gruels  possess  some  nutritive  value, 
since  they  contain  dextrin  and  maltose,  which  are  readily 
absorbed." 

A  simple  decoction  of  diastase  may  be  made  at  home  as 
follows.     A  tablespoonful  of  malted  barley  grains  is  put  in 


160  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

a  cup  and  enough  cold  water  added  to  cover  it.  This  should 
be  prepared  in  the  evening  and  placed  in  the  refrigerator  over- 
night. In  the  morning  the  water  is  strained  off  and  is  ready 
for  use.  The  diastases  on  the  market  or  most  of  the  thick 
malt  extracts  may  also  be  employed.  "  Cereo,"  an  active  glyce- 
rite  of  diastase,  is  now  especially  made  for  dextrinizing  gruels. 
In  cases  in  which  the  infant  cannot  take  milk  of  any  kind, 
Chapin  has  found  the  following  to  be  of  great  use : 

I.     Dextrinized  wheat  gruel,  eight  ounces  ; 
White  of  one  egg  (large) ; 
Two  even  teaspoonfuls  of  granulated  sugar. 

This  combination  gives  about  two  per  cent,  proteids  and  seven 
per  cent,  soluble  carbohydrates. 

II.     Dextrinized  wheat  gruel,  eight  ounces  ; 
Yolk  of  one  egg  (large) ; 
Two  even  teaspoonfuls  of  granulated  sugar. 

This  mixture  will  yield  about  1.7  per  cent,  fat,  1.7  per  cent, 
proteids,  and  seven  per  cent,  soluble  carbohydrates.  The  yolk 
also  contains  phosphorus  and  iron  in  organic  combination. 

Leeds  133  expresses  the  following  views  with  regard  to  the 
use  of  dextrinized  attenuants.  A  gummy  material  like  dextrin 
or  a  finely  divided  starch  like  that  in  oatmeal-  or  barley-water, 
along  with  more  or  less  glutinous  extractive  matter,  is  much 
better  adapted  to  serve  as  a  mechanical  attenuant  of  casein 
than  farinaceous  foods  in  their  ordinary  condition. 

Floyd  M.  Crandall  239  believes  that  the  secret  whereby 
the  specialist  may  succeed  in  finding  the  proper  proportions 
for  an  infant's  diet  more  quickly  than  the  practitioner  of  small 
experience  is  an  open  one, — namely,  to  begin  on  a  weak  mix- 
ture and  work  up  to  a  point  of  tolerance.  The  average  prac- 
titioner is  afraid  to  dilute  the  milk  sufficiently  at  the  outset, 
and  does  precisely  the  opposite. 

The  three  principal  items  to  remember  when  writing  for- 


MODERN   METHODS   OF   INFANT   FEEDING.  161 

mulae  at  the  bedside  are  these:  nine  ounces  of  top  milk 
contain  twelve  per  cent,  fat  and  four  per  cent,  proteids; 
eleven  ounces  of  top  milk  contain  ten  per  cent,  fat  and  four 
per  cent,  proteids;  fifteen  ounces  of  top  milk  contain  eight 
per  cent,  fat  and  four  per  cent,  proteids.  The  fact  that  one 
part  of  sugar  to  twenty  parts  of  mixture  will  give  a  percentage 
of  five  is  obvious. 

By  the  simplest  of  calculations  a  great  variety  of  formulae 
can  be  arranged.  The  one  source  of  error  lies  in  the  varying 
strengths  of  different  milks,  but  this  objection  applies  to  every 
method  of  home  modification. 

Louis  Fischer  171  calls  attention  to  the  fact  that  the  natu- 
ral food  of  an  infant  is  neither  boiled,  sterilized,  nor  pasteur- 
ized, and  believes  that  with  the  improved  hygiene  of  the  dairy 
it  is  safer  to  administer  raw  milk  and  thus  avoid  any  risk  of 
the  development  of  scurvy.  He  agrees  with  the  views  expressed 
by  Jacobi  regarding  the  employment  of  modified  Laboratory 
Milk.  In  his  own  experience,  children  fed  on  it  were  back- 
ward in  development  for  a  long  time  after  its  use.  They 
always  looked  anaemic  and  their  flesh  was  flabby,  although 
their  hygienic  surroundings  were  of  the  best.  He  thinks  that 
once  the  emulsion  is  destroyed  by  centrifugation  or  other 
mechanical  process  it  cannot  again  become  as  homogeneous  as 
before. 

Ashby  and  Wright  2  recommend  that  milk  should  be  pre- 
pared in  the  following  manner.  A  thirty-ounce  bottle  is  filled 
with  fresh  milk,  plugged  with  cotton,  and  placed  in  an  ice- 
chest  or  as  cool  a  place  as  possible  for  five  hours.  The  lower 
half  is  siphoned  off  and  replaced  with  an  equal  quantity  of 
seven  per  cent,  lactose  solution.  This  is  sterilized  at  160°  F. 
for  thirty  minutes,  cooled  rapidly,  and  kept  at  a  low  tempera- 
ture. The  quantity  to  be  given  at  each  feeding  must  be  heated 
to  100°  F.  before  administering.  With  good  milk  this  mixture 
will  contain  on  the  average  1.8  per  cent,  proteids,  from  three 
to  three  and  a  half  per  cent,  fat,  and  six  per  cent,  sugar. 

11 


162  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

For  very  young  or  delicate  infants  a  weaker  mixture  may  be 
made  by  siphoning  off  the  lower  two-thirds  of  the  milk  and 
adding  five  per  cent,  sugar  solution.  It  is  always  well  to 
render  it  alkaline  by  the  addition  of  a  few  grains  of  sodium 
bicarbonate  or  a  small  quantity  of  a  saturated  solution  of 
lime.  We  must  not  forget  that  milk  is  richer  in  winter,  when 
the  cows  are  stall-fed,  than  in  spring,  when  they  are  at  pas- 
ture. By  increasing  or  diminishing  the  time  of  standing  (five 
hours)  we  can  increase  or  diminish  the  proportion  of  fat. 
For  the  poorer  classes  milk  diluted  only  with  lime-water  or 
plain  water  must  be  used.  At  first  two-thirds  of  the  total 
quantity  should  consist  of  five  per  cent,  sugar  solution  and 
one-twentieth  lime-water.  For  a  new-born  baby  it  is  un- 
doubtedly best  to  begin  with  whey  or  diluted  peptonized  milk. 
After  the  first  three  or  four  weeks,  if  the  digestion  is  good, 
equal  parts  of  milk  and  sugar-water  and  one-tenth  lime-water 
may  be  used.  From  three  to  six  months  give  two-thirds  milk 
and  one-third  sugar-water. 

Whey  may  be  given  either  alone,  diluted  with  barley-water, 
or  as  a  diluent  for  milk  or  cream.  It  is  undoubtedly  true  that 
very  many  children  are  brought  up  on  diluted  cow's  milk 
without  cream  and  apparently  thrive  on  it.  Many  such  pass 
much  curd  in  their  stools  without  being  the  worse  for  it.  The 
amount  of  food  to  be  given  depends  partly  on  the  age,  partly 
on  the  powers  of  digestion  of  the  infant  and  the  degree  of 
its  development.  It  is  as  important  to  regulate  the  times 
for  feeding  and  the  amount  as  it  is  to  decide  on  the  nature 
of  the  food;  neither  age  nor  weight  should  be  taken  blindly 
as  a  guide  to  the  amount  of  food  that  the  infant  should 
take. 

At  one  month  (weight  from  six  to  eight  pounds)  give  from 
one  to  two  ounces  every  two  and  a  half  hours.  Eight  bottles 
are  required,  with  a  total  content  of  from  twelve  to  fifteen 
ounces. 

At  two  months  (weight  from  eight  to  eleven  pounds)  give 


MODERN   METHODS   OF   INFANT   FEEDING.  163 

from  three  to  four  ounces  every  two  and  a  half  hours.  Eight 
bottles  are  needed,  containing  from  twenty  to  thirty  ounces 
in  all. 

From  three  to  four  months  (weight  from  eleven  to  four- 
teen pounds)  give  from  four  to  five  ounces  every  three  hours. 
Seven  bottles  are  needed,  containing  from  thirty  to  thirty-five 
ounces  in  all. 

For  the  fifth  and  sixth  months  (weight  from  fourteen  to 
sixteen  pounds)  give  from  six  to  seven  ounces  every  three 
hours.  Six  bottles  are  needed,  and  the  total  quantity  is  from 
thirty-five  to  forty  ounces. 

Ashby  believes  that  the  addition  of  thin  starchy  fluids,  such 
as  barley-  and  oatmeal-water,  after  the  third  or  fourth  month 
checks  rapid  curdling  of  the  milk  and  is  of  considerable  value 
for  the  infant's  nutrition.  In  some  cases  milk  so  diluted  is 
better  assimilated  than  when  plain  water  is  used.  Under 
three  to  four  months  starch  should  be  dextrinized. 

Barley  jelly,  whole  meal,  maize,  or  oatmeal  may  be  added 
to  the  diet  at  six  or  seven  months,  provided  they  are  not  in 
too  concentrated  solution  to  pass  through  the  nipple.  At 
seven  months  the  child  may  have  a  crust  to  nibble  on,  but  no 
other  solid  food,  such  as  eggs. 

Cautley  38  advises  the  following  dilutions  during  the  early 
months  of  life.  The  figures  represent  teaspoonfuls.  Lime- 
water  is  to  be  added  after  boiling;  if  cream  cannot  be  ob- 
tained, take  an  extra  teaspoonful  of  top  milk : 


First  week.  Second  week.  Third  week.  Fourth  week. 

Milk 2  3  4  5 

Cream 1  1  1  1 

Water 5  6  7  8 

Lime-water 1  1  1  1 


One  lump  of  sugar  is  to  be  added  to  each  feeding. 


164 


THE   ARTIFICIAL   FEEDING   OF   INFANTS. 


Third  to  sixth 
month. 


Sixth  to  ninth 
month. 


-4  tablespoonfuls   5-6  tablespoonfuls 

-4  tablespoonfuls   5-6  tablespoonfuls 
1-4  teaspoonfuls 


Two  months. 
Boiled  cow's  milk .     2  tablespoonfuls 

Boiled  water 2  tablespoonfuls 

Barley-water 

Cream ...     1  teaspoonful 

Lime-water 3  teaspoonfuls       

When  cream  cannot  be  obtained,  cod-liver  oil  may  be  used  instead  after 
the  sixth  month.    One  lump  of  sugar  is  to  be  added  to  each  of  the  mixtures. 

Cautley  believes  that  after  the  age  of  two  months  most 
infants  can  take  milk  diluted  equally  with  water;  in  some  cases 
it  is  necessary  to  still  further  dilute  the  milk  (even  seven  or 
eight  times),  but  by  sufficient  dilution  at  first  any  infant  can 
become  accustomed  to  take  cow's  milk.  In  his  experience, 
cane-sugar  can  readily  replace  lactose  without  any  ill  effect, 
if  given  in  the  correct  proportion.  Milk-sugar  ferments  very 
much  more  readily  than  cane-sugar.  When  the  milk-supply 
is  adequate,  starch  should  not  be  given  to  young  infants  (ex- 
cept in  small  quantities  and  in  very  weak  solution)  until  the 
time  of  weaning.  The  appearance  of  six  teeth  may  be  con- 
sidered an  indication  for  its  administration.  Barley-water 
sometimes  causes  starchy  indigestion.  Stale  bread,  biscuit, 
crackers,  and  corn  flour  may  be  used  towards  the  end  of  the 
first  year. 

Dextrinized  attenuants  act  mechanically.  Oatmeal  contains 
more  starch  than  barley-water  and  wheat  more  than  either. 
The  latter  is  therefore  less  easily  acted  on  by  the  saliva. 

Fenwick  52  advises  the  following  mixtures  for  routine  use 
during  the  first  year  of  the  infant's  life. 

First  week: 


Cream 2  teaspoonfuls 

"Whey 3  teaspoonfuls 

Lactose 10  grains 

"Water 3  teaspoonfuls 


Cow's  milk 1  tablespoonful 

Barley-water ...   1  tablespoonful 
Lactose 15  grains 


MODERN    METHODS   OF   INFANT   FEEDING. 


165 


From  the  second  to  the  fourth  week  give  each  second  hour 
from  four  a.m.  to  ten  p.m.  : 


Cream 2  teaspoon fuls 

Cow's  milk 1  tablespoonful 

Lactose 15  grains 

Water 1  ounce 


Cow's  milk  ....  6  teaspoonfuls 
Barley-water ...  5  teaspoonfuls 
Lactose 15  grains 


For  the  third  month  give  each  two  and  a  half  hours  from 
five  a.m.  to  eleven  p.m.  : 


Cream 3  teaspoonfuls 

Cow's  milk  ...  .12  teaspoonfuls 

Lactose 28  grains 

Water 1  ounce 


Cream 3  teaspoonfuls 

Cow's  milk  ...  .12  teaspoonfuls 

Lactose 30  grains 

Barley-water ...  12  teaspoonfuls 


For  the  fourth  month  give  each  two  and  a  half  hours  from 
five  a.m.  to  eleven  p.m.  : 


Cream 3£  teaspoonfuls 

Cow's  milk  ...  .12  teaspoonfuls 

Lactose 40  grains 

Water 2  ounces 


Cream 4  teaspoonfuls 

Cow's  milk  ....  2  ounces 

Lactose 45  grains 

Barley-water ...  2  ounces 


For  the  fifth  month  give  each  three  hours  from  five  a.m.  to 
eleven  p.m.  : 


Cream 4  teaspoonfuls 

Cow's  milk  ....   2  ounces 

Lactose 50  grains 

Water 1  \  ounces 


Cream 5  teaspoonfuls 

Cow's  milk  ...  .18  teaspoonfuls 

Lactose 1  teaspoonful 

Barley-water ...  2  ounces 


For  the  sixth  month  give  each  three  hours  from  five  a.m. 
to  eleven  p.m.  : 


Cream 4  teaspoonfuls 

Cow's  milk  ...  .20  teaspoonfuls 

Lactose 1  teaspoonful 

Water 1  ounce 


Cream 5  teaspoonfuls 

Cow's  milk  ...  .20  teaspoonfuls 

Lactose 1  teaspoonful 

Barley-water . . .  1  \  ounces 


166  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

From  six  to  twelve  months  the  first  meal  should  be  at  seven 
a.m.  :  one  teacupful  of  dilute  alkaline  milk,  humanized  milk, 
or  cream  mixture.  Second  meal  at  10.30  a.m.  :  milk  as  above, 
with  a  teaspoonful  of  malted  food  such  as  Mellin's  Food,  or 
bread  jelly,  or  two  teaspoonfuls  of  barley  jelly.  The  third  and 
fourth  meals  should  be  as  above  at  two  p.m.  and  six  p.m. 
The  last  meal  is  to  be  given  at  9.30  p.m.  or  ten  p.m.,  and  should 
be  like  the  first.  After  seven  months  one  teaspoonful  of  whole 
meal  flour  may  be  used  instead  of  Mellin's  Food,  or  a  little 
fine  oatmeal  porridge  may  be  allowed  at  the  first  meal.  If 
indigestion  follows  or  the  infant  ceases  to  gain,  the  food  should 
be  predigested  with  malt.  After  the  ninth  month  the  yolk 
of  a  soft-boiled  egg  may  be  given  for  the  third  meal,  or  a  cup 
of  veal,  chicken,  mutton,  or  beef  broth  with  stale  bread-crumbs. 

Fenwick  advises  the  use  of  lime-water  in  the  milk  in  the  pro- 
portion of  one  to  twenty,  to  render  it  alkaline,  and  considers 
that  barley-water  is  preferable  to  plain  water  as  a  mechanical 
diluent. 

John  Thomson  143  allows  the  healthy  infant  to  take  as 
much  as  it  wants  at  regular  hours  of  feeding.  As  a  general 
rule,  for  the  first  six  weeks  of  life  he  uses  milk  diluted  with 
two  or  three  times  its  bulk  of  water;  from  one  and  a  half 
to  four  or  five  months,  equal  parts  of  milk  and  water;  from 
the  fifth  to  the  eighth  or  ninth  month,  two  parts  of  milk  and 
one  part  of  water,  increasing  after  this  until  at  the  end  of 
the  year  pure  milk  is  given.  In  difficult  cases  he  makes  use 
of  Frankland's,  Meigs's,  or  Botch's  mixtures. 

To  neutralize  the  acidity,  he  recommends  the  use  of  lime- 
water  in  the  proportion  of  one-sixth  to  one-eighth;  sodium 
bicarbonate  or  magnesia  may  be  used  instead.  The  percentage 
of  sugar  should  be  brought  up  to  normal  by  the  addition  of 
lactose  or,  if  this  is  not  obtainable,  cane-sugar. 


CHAPTER    VI. 


WEANING. 


Authorities  are  nearly  in  accord  as  to  the  proper  time 
to  institute  weaning.  If  the  child  is  thriving  and  showing 
satisfactory  gain  in  weight  and  development,  breast-milk  alone 
is  sufficient  until  the  ninth  to  the  twelfth  month  (Starr, 
J.  Lewis  Smith,  Williams,  Cautley,  Ashby  and  Wright,  Thom- 
son, Bendix,  Monti,  Gerhardt,  Marfan,  Taylor  and  Wells,  Cro- 
zer  Griffith,  etc.). 
**  Comby  prefers  to  wean  late  (from  the  fifteenth  to  the  eigh- 
teenth or  twentieth  month)  ;  he  advises  that  the  breast  and 
the  bottle  should  be  given  alternately.  Marfan  also  thinks 
that  it  is  advisable  to  keep  the  infant  at  the  breast  until  the 
sixteenth  month,  but  not  after  the  eighteenth  month,  giving 
in  addition  artificial  food.  The  breast-milk  may  prove  a  great 
resource  in  case  of  illness.  A  good  indication  for  the  adminis- 
tration of  other  food  than  that  from  the  breast  is  the  cutting 
of  four  teeth,  showing  that  the  development  of  the  digestive 
tract  is  advancing. 

On  the  other  hand,  Monti  is  inclined  to  believe  that  breast- 
feeding after  the  twelfth  month  is  apt  to  result  in  malnutri- 
tion, anaemia,  etc.  Infants  so  fed  may  be  fat,  but  will  not 
necessarily  be  strong.  Ashby  expresses  similar  views.  (These 
remarks  seem  to  apply  to  infants  fed  solely  at  the  breast. — 
Editors.) 

Rarely  it  may  be  necessary  to  wean  early — at  the  age  of 
five  or  six  months — if  anomalies  in  the  mother's  milk  develop 
or  if  the  infant  is  not  making  satisfactory  progress.  In  the 
latter  case  it  is  well  to  add  artificial  nourishment  to  the  diet, 
but  not  to  wean  entirely  until  the  necessary  physiological  de- 
velopment has  taken  place." 

167 


V 


168  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

The  child  should  not  be  weaned  during  the  hot  months  of 
the  year,  nor  during  or  immediately  after  an  illness,  nor  during 
a  gastro-intestinal  disturbance,  unless  this  is  due  to  a  per- 
sistent faulty  composition  of  the  breast-milk. 

Mixed  Feeding. 

Mixed  feeding  is  preferable  to  insufficient  nourishment  from 
the  breast,  and  is  to  be  preferred  to  exclusive  artificial  feeding. 
The  breast  and  bottle  should  be  given  alternately,  and  both 
breasts  should  be  given  at  each  nursing  to  maintain  their 
secretion  (Marfan).  The  value  of  mixed  feeding  is  univer- 
sally admitted. 

Indications  for  Weaning. 

Monti."  I.  Eepeated  profuse  menstruation  (during  which 
the  child  loses  weight  on  account  of  changes  in  the  composition 
of  the  milk). 

II.  Pregnancy  (requires  immediate  weaning). 

III.  Acute  infectious  febrile  disorders  (unless  of  very  short 
duration). 

IV.  Failure  of  the  child  to  thrive. 

(The  last  indication  calls  for  mixed  feeding  rather  than  for 
absolute  weaning,  unless  careful  analysis  of  the  mother's  milk 
shows  that  it  is  entirely  unsuited  to  the  needs  of  the  infant. — 
Editors.) 

Opinions  differ  as  to  the  effects  of  menstruation  and  preg- 
nancy on  the  secretion  of  the  breasts.  Marfan  thinks  that 
under  ordinary  circumstances  the  return  of  the  menses  does 
not  necessitate  weaning,  unless  marked  digestive  disturbances 
occur  and  the  child  ceases  to  gain  for  a  certain  length  of  time. 
Pregnancy  is  not  incompatible  with  nursing ;  if  the  mother  is 
strong  and  healthy,  she  can  nurse  her  child  until  the  latter 
months  of  gestation.  The  mother's  condition  and  the  amount 
of  milk  she  secretes  must  decide  the  question  (Bendix). 

Comby  62  considers  that  the  return  of  the  menses  should 


WEANING.  169 

never  demand  immediate  weaning.  There  may  be  some  tem- 
porary disturbance,  but  one  should  not  on  this  account  wean 
prematurely. 

Bendix,226  from  the  careful  study  of  one  hundred  and  forty 
cases,  concludes  that  the  mere  occurrence  of  menstruation  is 
insufficient  ground  for  weaning,  even  when  alterations  take 
place  in  the  quality  and  quantity  of  the  milk,  since  these 
changes  are  of  a  temporary  character  only  and  will  not  seri- 
ously affect  the  child's  condition.  He  also  considers  that  the 
infectious  fevers  are  not  a  contraindication  to  nursing.  In 
one  case  of  measles,  one  of  scarlet  fever,  and  one  of  influenza 
the  mothers  were  able  to  nurse  their  babies  throughout  the  dis- 
eases and  the  infants  remained  healthy  (except  for  a  slight 
dyspeptic  attack  in  the  latter  case).  Tuberculosis  is  of  course 
a  positive  contraindication  to  nursing. 

Taylor  and  Wells  147  think  that,  as  a  general  rule,  it  is 
best  to  wean  on  the  diagnosis  of  pregnancy  being  established, 
since  this  disturbs  the  equilibrium  of  the  milk  secretion.  Usu- 
ally, too,  the  continuance  of  menstruation  affects  the  compo- 
sition of  the  milk  to  a  marked  degree.  According  to  Eotch, 
there  is  a  decided  increase  in  the  proteids  and  a  diminution 
in  the  fat.  By  emptying  the  breasts  with  a  pump  these  periods 
may  be  tided  over  and  the  necessity  to  wean  may  be  averted. 

Holt.183  It  is  important  that  the  physician  should  be  fa- 
miliar with  the  symptoms  of  inadequate  nursing.  During  IJie 
first  days  of  life  an  important  sign  is  a  rise  of  temperature 
to  101°  or  102°  F.,  or  higher,  without  obvious  signs  of  ill- 
ness. 

Symptoms  of  inadequate  nursing  may  be  grouped  as  follows : 
colic,  fretfulness,  loss  of  sleep,  with  either  no  gain  in  weight 
or  a  loss  of  several  ounces  a  week,  and  abnormal  stools.  All 
of  these,  persisting  beyond  the  third  or  fourth  week  of  the 
mother's  convalescence,  justify  immediate  weaning. 

"  Since  artificial  feeding,  when  properly  carried  out,  gives 
so  much  better  results  than  poor  or  doubtful  nursing,  it  is 


170  THE   ARTIFICIAL   FEEDING    OF    INFANTS. 

better  to  stop  nursing  after  a  fair  trial — i.e.,  two  weeks — has 
been  made  rather  than  waste  time  in  prolonged  efforts  to 
improve  the  breast-milk." 

Method  of  Weaning. 

All  authorities  are  agreed  that  it  is  advisable  to  wean  gradu- 
ally; the  time  required  for  gradual  weaning  is  from  two  to 
five  weeks.  For  instance,  Monti  says  to  give  one  extra  meal 
a  day  for  one  week,  two  a  day  during  the  next  week,  three  a 
day  during  the  third  week,  and  so  on.  At  the  end  of  four  or 
five  weeks  cease  nursing  altogether. 

Undoubtedly  the  best  food  with  which  to  wean  a  child  is 
properly  prepared  cow's  milk.  The  child  has  to  learn  to  digest 
cow's  milk  casein  just  as  in  the  early  months  of  life,  but  with 
much  greater  probability  of  success.  It  is  safer,  therefore,  to 
begin  with  a  high  dilution  of  cow's  milk,  such  as  one  part  of 
milk  to  two  parts  of  water,  with  the  addition  of  cream  if 
desired.  If  this  agrees,  the  strength  of  the  mixture  can 
rapidly  be  increased  until  at  the  end  of  two  weeks  equal  parts 
of  milk  and  water  and  at  the  end  of  one  month  three  parts 
of  milk  to  one  of  water  or  whole  cow's  milk  may  be  given.  If 
weaning  is  carried  out  before  the  tenth  month,  a  longer  time 
may  be  necessary,  and  for  infants  of  weak  digestion  higher 
dilutions  or  special  mixtures  may  be  required.  In  preparing 
the  milk  mixture  for  weaning  it  will  usually  be  found  advan- 
tageous to  use  a  starchy  decoction,  such  as  barley-water,  for 
our  diluent  instead  of  plain  water,  or  to  add  one  of  the  reli- 
able infant  foods.  This  addition  of  starch  is  indicated  not 
only  to  render  the  milk  more  digestible,  but  also  to  increase 
the  proportion  of  carbohydrates.  Holt's  rules  (see  page  139) 
for  the  feeding  of  difficult  cases  during  the  second  year  hold 
good  for  any  case  in  which  the  digestion  of  cow's  milk  offers 
special  difficulty.  Again,  many  children  do  well  on  milk  mix- 
tures, but  suffer  from  repeated  attacks  of  indigestion  following 
the  administration  of  solid  food.     Starches  in  concentrated 


WEANING.  171 

form,  such  as  cakes,  bread,  potatoes,  oatmeal,  etc.,  will  gen- 
erally be  found  to  be  the  articles  at  fault;  their  withdrawal 
and  the  substitution  of  milk  and  broths  will  usually  be  fol- 
lowed by  complete  recovery.  The  common  practice  of  giving 
the  infant  a  "  taste"  of  tea,  coffee,  or  alcoholic  beverages  need 
only  be  mentioned  to  be  condemned.  Under  the  following 
headings  we  have  included  those  articles  of  food  which  may 
form  the  child's  diet  from  the  time  of  weaning  until  the  end 
of  the  second  year.  Experience  has  shown  that  infants  do  best 
on  plain  food.  Once  the  child  has  acquired  a  taste  for  sweets 
and  highly  seasoned  articles  of  food  it  will  rarely  be  satisfied 
without  them;  therefore  it  is  much  kinder  to  withhold  such 
articles  absolutely  until  a  later  period  of  life. 

Starches. 
After  the  ninth  month  starches  may  be  given  to  healthy 
infants,  and  sometimes  earlier,  provided  five  or  six  incisors 
have  appeared  and  there  is  an  abundance  of  saliva  present. 
The  best  preparations  of  starch  are  thoroughly  cooked  gruels 
or  jellies  and  the  infant  foods,  preferably  those  which  are 
dextrinized  or  malted;  ""Infant's  Zwieback"  may  also  be 
recommended.  If  one  of  the  infant  foods  is  selected,  begin 
by  adding  one  teaspoonful  to  the  milk  mixture  once  or  twice 
a  day,  increasing  gradually  to  a  tablespoonful  at  each  feeding, 
if  it  is  well  tolerated.  When  the  child  is  one  year  of  age  we 
may  add  stale  bread-crumbs  to  the  diet  once  or  twice  a  day 
mixed  with  the  milk  or  with  meat  broth ;  or  the  child  may  be 
given  a  hard  crust  of  bread  to  chew.  If  signs  of  indigestion 
supervene,  we  must  immediately  reduce  the  amount  of  starchy 
food;  it  may  be  necessary  to  cut  it  off  altogether  if  the  diges- 
tive disturbance  is  marked.  Some  children  cannot  digest 
starch  until  the  end  of  their  second  year.  Fermentation  of 
starchy  food  causes  colic  and  diarrhoea,  but  seldom  gives  rise 
to  marked  constitutional  disturbance,  in  contradistinction  to 
the  enteritis  following  "milk  infection." 


172  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

Meat  Broths. 
Mutton,  veal,  chicken,  or  beef  broth  may  be  given  to  the 
child  when  he  is  one  year  old.  Their  use  is  indicated  before 
this  time  if  the  child  has  rickets  or  gastro-intestinal  disturb- 
ances. One  cupful  (from  six  to  eight  ounces)  of  broth  with 
the  fat  carefully  removed  may  take  the  place  of  a  milk  feed- 
ing in  the  middle  of  the  day.  The  broth  may  be  thickened 
with  a  starchy  gruel,  or  its  nutritive  value  increased  by  the 
addition  of  the  yolk  of  an  egg  (during  the  second  year),  or 
cream  may  be  added  to  it  for  infants  with  weak  digestions. 

Raw  Beef  Juice. 
This  is  one  of  the  most  assimilable  forms  of  albuminoid 
food.  It  can  be  given  with  safety  to  an  infant  over  one  year 
of  age  in  doses  of  from  half  an  ounce  to  an  ounce.  From  one 
to  three  ounces  may  be  given  during  the  twenty-four  hours. 
The  administration  of  beef  juice  to  infants  under  one  year 
may  be  desirable  in  cases  of  rickets,  scurvy,  malnutrition,  etc. 
One  teaspoonful  may  be  given  once  or  twice  a  day  to  a  child 
nine  months  old. 

Scraped  Meat  (Beef  or  Mutton). 
This  can  form  part  of  the  healthy  child's  diet  during  the 
second  half  of  the  second  year.  Rotch  prefers  not  to  begin 
its  administration  until  the  first  half  of  the  third  year.  One 
tablespoonful  may  be  given  once  a  day  at  the  midday  meal, 
to  take  the  place  of  the  beef  juice.  It  should  not  be  given 
to  infants  with  weak  digestion.  Cautley  allows  white  meat 
of  chicken  at  this  period. 

Yolk  of  Egg. 
This  can  be  added  to  a  pint  of  meat  broth  or  to  a  starchy 
gruel.    It  is  a  convenient  means  of  adding  fat  to  the  diet,  but 
we  must  remember  that  it  is  not  as  easily  assimilated  as  good 


WEANING.  1 73 

cream.  Since  the  yolk  of  one  egg  contains  thirty-two  per  cent, 
fat  (Konig),  it  must  be  well  diluted  to  render  it  digestible. 
A  vigorous,  healthy  infant  may  be  given  the  yolk  of  egg  at 
the  age  of  nine  or  ten  months,  but  in  the  majority  of  cases 
it  is  well  to  wait  until  the  child  is  from  twelve  to  eighteen 
months  old  before  making  this  addition  to  the  diet.  A  soft- 
boiled  egg  may  be  given  once  or  twice  a  week  after  the  six- 
teenth month.     Cautley  allows  custard  at  this  age. 

Bread  and  Butter. 
A  small  slice  of  stale  bread,  plain  or  toasted  and  thinly 
buttered,  is  permissible  after  the  first  year,  and  may  form 
part  of  the  daily  diet.     Eye,  Graham,  or  whole  wheat  bread 
may  be  used  if  the  child  is  constipated. 

Eice,  Potato,  Hominy,  etc. 
One  large  tablespoonful  of  well-boiled  rice  or  hominy,  mixed 
with  milk,  may  be  given  to  a  healthy  child  for  its  dinner  two 
or  three  times  a  week  during  the  latter  half  of  the  second  year. 
In  place  of  it,  the  child  may  have  one  tablespoonful  of  thor- 
oughly baked  well-mashed  potato,  with  a  little  butter  and 
salt.  Beef  gravy  may  take  the  place  of  the  butter.  Monti 
allows  puree  of  peas. 

Green  Vegetables. 
A  small  quantity  of  well-boiled  spinach  is  allowed  now  and 
then  by  Monti  and  Cautley  after  the  eighteenth  month.     Fen- 
wick  gives  occasionally  a  little  stewed  celery,  well-cooked  as- . 
paragus  tips,  or  cauliflower. 

Dessert. 
One  or  two  tablespoonfuls  of  junket,  custard,  or  plain  rice 
and  milk  pudding  may  be  given  with  the  dinner  to  a  healthy 
child  during  the  second  year.     Cautley  allows  farina,   and 
Fenwick  sago  and  tapioca  pudding. 


174  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

Fruit. 
Orange  juice  is  a  valuable  addition  to  the  child's  diet  and 
possesses  antiscorbutic  properties.  It  may  be  given  in  tea- 
spoonful  doses,  increased  to  one  or  two  ounces  at  the  end 
of  the  first  year.  Apple  sauce,  the  soft  part  of  two  or  three 
stewed  prunes,  or  a  slice  of  baked  apple  is  admissible  during 
the  latter  half  of  the  second  year.  Rotch  allows  a  ripe  peach 
at  this  age. 

Holt.183  Milk  should  be  the  basis  of  the  diet  during  the 
second  year  of  life.  The  child  should  be  weaned  from  the 
bottle  by  the  thirteenth  to  the  fifteenth  month,  except  perhaps 
the  night  feeding.  For  the  average  case  little  modification 
of  the  milk  is  necessary  unless  it  be  very  rich,  when  it  should 
be  diluted  one-fourth  or  more,  during  the  hot  weather  espe- 
cially. If  the  milk  is  poor  in  fat,  use  the  upper  two-thirds 
of  the  bottle. 

Farinaceous  gruels  may  advantageously  be  added  to  the  milk 
mixtures.  The  total  quantity  of  liquid  food  to  be  given  during 
the  first  six  months  of  the  second  year  should  be  from  forty 
to  fifty  ounces  a  day;  during  the  last  six  months  this  quan- 
tity should  be  increased  to  forty-five  or  fifty-five  ounces. 

D.  J.  Milton  Miller  109  advises  that  the  diet  in  the  second 
year  should  be  largely  nitrogenous  with  a  minimum  of  carbo- 
hydrates, the  latter  to  be  given  in  the  form  of  gruels  or  jel- 
lies. Bread  must  not  be  used  before  the  end  of  the  second  year, 
unless  crushed  and  mixed  with  milk;  it  must  be  well  dried  in 
the  oven,  or  we  may  use  zwieback  instead.  Of  course  many 
children  can  digest  farinacea  well  during  the  second  year; 
to  insure  the  best  results,  however,  we  must  be  cautious  in 
the  administration  of  starchy  foods,  which  are  such  a  frequent 
cause  of  indigestion  during  the  second  and  third  years  of  the 
child's  life. 

Jacobi.76    Beef  and  meat  broths  may  be  given  towards  the 


WEANING.  175 

end  of  the  first  year,  or  at  any  time  in  rickets;  mutton  broth 
should  be  used  if  there  is  a  tendency  to  diarrhoea.  Beef  tea 
contains  much  salt,  and  hence  it  is  dangerous  to  give  it  in 
summer  diarrhoea;  it  is  low  in  albuminoids,  and  may  be  ren- 
dered more  nutritious  by  the  addition  of  farinacea  or  egg 
albumin.  Beef  broth  is  about  as  rich  in  albuminoids  as  whey ; 
it  contains  extractives,  creatin,  and  creatinin.  It  should  not 
be  given  when  there  is  gastric  irritation,  gastritis,  or  acute 
dysentery.  Veal  broth  is  liable  to  increase  diarrhoea  and 
mutton  broth  to  increase  constipation. 

Peptonized  beef  preparations  are  valuable,  but  the  condition 
of  the  digestive  organs  must  be  carefully  considered.  The 
last  product  of  gastric  digestion  is  albumose.  The  formation 
of  peptone  is  not  completed  till  the  action  of  the  pancreatic 
ferments  and  perhaps  certain  intestinal  bacteria  has  mani- 
fested itself.  Peptone  can  be  formed  without  the  presence 
of  hydrochloric  acid.  Scraped  raw  beef  is  easy  of  digestion; 
it  is  of  use  in  the  chronic  stage  of,  and  during  convalescence 
from,  gastro-intestinal  catarrh. 

White  meat,  such  as  chicken,  contains  less  fat,  haemoglobin, 
and  extractives  than  beef.  The  white  of  egg  alone  may  be 
valuable  for  temporary  use,  or  it  may  be  given  as  a  permanent 
addition  to  other  food. 

J.  Rudisch  has  devised  the  following  method  of  preparing 
milk  for  infants  with  gastric  catarrh  or  who  cannot  digest 
milk  in  its  usual  form.  He  mixes  from  twenty-five  to  thirty 
minims  of  dilute  hydrochloric  acid  with  a  pint  of  water,  adds 
a  quart  of  milk,  and  boils  for  a  few  moments.  This  prepara- 
tion keeps  well,  is  palatable,  and  highly  digestible.  Bunker 
has  recently  called  attention  to  this  method. 

Somatose  is  worthy  a  trial  because  it  does  not  contain  those 
nucleins  which  irritate  the  kidneys  and  because  it  is  a  genuine 
albumose:  one  teaspoonful  contains  as  much  albumin  as  half 
an  egg  or  three  tablespoonfuls  of  milk. 

The  artificial  farinaceous  foods,  in  which  starch  is  more  or 


176  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

less  transformed  into  dextrin,  fill  a  gap  for  those  rare  cases 
in  which  milk,  though  ever  so  well  prepared,  or  the  cereals, 
such  as  oatmeal  and  barley,  are  not  well  tolerated. 

Extract  of  malt  contains  albuminoids,  fifty-three  per  cent, 
of  sugar,  and  fifteen  per  cent,  of  dextrin;  one  tablespoonful 
of  it  is  equivalent  in  nutritive  value  to  one  egg.  It  may  be 
serviceable;  it  is  very  nutritious  on  account  of  its  richness 
in  sugar,  and  should  be  utilized  oftener  than  seems  to  be 
usual. 

Monti  "  states  that  cereal  coffee  may  be  used  as  an  addition 
to  the  milk  in  cases  in  which  the  digestion  is  poor  (rickets, 
scrofula,  etc.),  and  likewise  cocoa.  Neither  contains  enough 
fat  or  albumin  to  be  of  much  nutritive  value.  Tea  and  coffee, 
especially  black  coffee,  are  useful  stimulants  for  collapse  and 
heart  weakness  in  infants;  in  fact,  in  many  cases  they  are 
preferable  to  alcohol.  After  the  eighteenth  month  a  small 
amount  may  be  added  to  the  milk  without  hurting  the  child 
and  with  no  danger  to  the  nervous  system  (  ?  Editors). 

Alcohol  is  not  needed  normally.  Used  judiciously,  it  has 
decided  value  in  furthering  digestion  in  weak,  sickly,  and 
anaemic  children.  Brandy,  wines  (with  a  low  percentage  of 
alcohol),  and  beer  may  be  used. 

Water  should  be  given  with  each  meal  (from  five  to  seven 
ounces  at  least). 

For  purposes  of  comparison  as  well  as  clearness,  we  have 
tabulated  the  diet  lists  (during  the  second  nutritive  period) 
of  Fenwick,  Starr,  and  Cautley. 

Diet  for  the  Second  Nutritive  Period  (Twelve  to 
Eighteen  Months). 

First  Meal  from  Six  to  Eight  A.M. 
Starr.133    A  slice  of  stale  bread  soaked  in  a  cup  of  fresh 
milk,  or  the  lightly  boiled  yolk  of  one  egg  with  bread-crumbs 
and  milk. 


WEANING.  177 

Fenwick.52  From  eight  to  ten  ounces  of  milk  with  a  slice 
of  thin  bread  and  butter  or  rusk,  or  milk  and  a  teaspoonful 
of  Quaker  oats. 

Second  Meal  from  Nine  to  10. SO  A.M. 

Starr.  Six  ounces  of  milk  with  a  thin  slice  of  buttered 
bread  or  a  soda  biscuit. 

Cautley.38  A  bowl  of  thick  gruel  or  oatmeal  porridge,  or 
a  cup  of  cocoa  and  milk  with  bread  and  butter. 

Fenwick.    Milk  and  rusk  or  plain  biscuit. 

Third  Meal  from  One  to  Two  P.M. 

Starr.  A  cup  of  meat  broth  with  a  slice  of  bread  and  one 
tablespoonful  of  rice  and  milk  pudding,  or  a  mashed  baked 
potato  moistened  with  one  or  two  ounces  of  beef  tea,  and  two 
tablespoonfuls  of  junket. 

Fenwick.  Tapioca  or  sago  pudding  may  be  used  instead 
of  the  rice  pudding,  and  a  little  stewed  fruit  may  be  given 
once  or  twice  a  week. 

Cautley.  The  lightly  boiled  yolk  of  an  egg  or  a  poached 
egg  with  stale  bread;  stale  bread-crumbs  in  beef  tea,  soup, 
or  broth,  and  a  large  tablespoonful  of  custard,  corn  flour, 
or  blanc-mange. 

Fourth  Meal  from  Five  to  Six  P.M. 
Same  as  the  first  or  second. 

Fifth  Meal  from  Nine  to  Ten  P.M. 
Starr.     Half  an  ounce  of  Mellin's  Food  with  half  a  pint 
of  milk. 

Cautley.  A  cup  of  milk  gruel  made  with  rice,  tapioca, 
sago,  or  hominy ;   or  rusk  or  lady-finger. 

In  Starr's  opinion,  the  fifth  meal  is  often  unnecessary  and 
the  child  should  never  be  wakened  for  it.  If  the  child  wakes 
early  in  the  morning,  it  should  be  given  a  cup  of  warm  milk. 

12 


178  THE   ARTIFICIAL   FEEDING    OF   INFANTS. 

Diet  eor  the  Second  Nutritive  Period  (Eighteen  Months 
to  Two  Years). 

First  Meal  from  Seven  to  7.30  A.M. 

Starr.  Half  a  pint  of  fresh  milk,  the  yolk  of  an  egg,  and 
two  slices  of  bread  and  butter. 

Cautley.  One  ounce  of  well-cooked  oatmeal  or  wheaten 
grits  with  sugar  and  cream,  and  a  glass  of  milk. 

Second  Meal  from  10.30  to  Eleven  A.M. 
Starr.    Milk  and  bread  and  butter  or  a  soda  biscuit. 
Fen  wick.    In  addition  to  the  above,  treacle,  sugar,  or  mar- 
malade. 

Third  Meal  from  1.30  to  Taw  P.M. 

Starr.  Eight  ounces  of  beef,  mutton,  or  chicken  broth  with 
a  slice  of  stale  bread  and  butter  and  a  saucer  of  rice  and  milk 
pudding ;  or  half  an  ounce  of  underdone  mutton  pounded  to  a 
paste,  and  a  mashed  baked  potato  moistened  with  dish  gravy 
and  a  saucer  of  junket. 

Fenwick.  Custard,  tapioca,  or  rice  pudding ;  finely  minced 
mutton-chop  or  a  boiled  egg;  stewed  celery,  well-cooked  as- 
paragus, or  cauliflower  may  be  given  occasionally  with  dinner. 
When  the  first  set  of  molars  are  cut,  a  small  amount  of  boiled 
sole  or  cod  or  finely  minced  boiled  fowl  may  be  given. 

Cautley  allows  spinach,  and  Ashby  and  Wright  2  stewed 
apples  and  preserves. 

Fourth  Meal  at  6.30  P.M. 

Starr.  A  cup  of  milk  with  bread  and  butter,  or  toast,  or 
milk  toast. 

Fenwick.  The  yolk  of  an  egg  lightly  boiled,  or  cocoatina 
(half  a  drachm  to  six  ounces  of  milk),  or  treacle. 


CHAPTEE   VII. 
CARE  OF  THE  MILK. 

It  is  scarcely  necessary  to  describe  in  detail  the  numerous 
ways  in  which  milk  may  become  contaminated  during  the 
process  of  milking.  To  those  who  are  not  familiar  with  the 
conditions  at  the  average  dairy  farm,  it  is  evident  that  when 
the  udder  and  teats  of  the  cow  are  not  washed,  and  the  hands 
of  the  milkers,  the  milk-pails,  and  utensils  only  hastily  and 
imperfectly  cleansed,  the  opportunities  for  milk  infection  are 
manifold. 

It  is  interesting  to  follow  such  milk  from  the  time  when  it  is 
drawn  until  it  reaches  the  consumer;  unfortunately,  much  the 
larger  portion  of  the  city's  supply  meets  with  the  following 
treatment.  The  milk  drawn  in  the  morning,  after  being  aerated 
by  pouring  from  can  to  can,  is  taken  from  the  various  farms 
to  the  nearest  railroad  station,  where  it  stands  in  its  forty- 
gallon  cans  until  removed  to  the  distributing  stations  in  the 
city.  From  these  the  various  small  milk  dealers  remove  it  as 
soon  as  feasible  to  their  dairies.  During  this  time  no  attempt 
has  been  made  to  keep  the  milk  cool  other  than  the  use  of  a 
protector  over  each  can  in  the  wagon. 

With  the  morning's  milk  is  also  sent  the  milk  of  the  pre- 
vious evening,  which  has  been  kept  cool  (probably  from  50° 
to  54°  F.)  through  the  night.  When  the  dairy  supply  is  at  a 
great  distance  from  the  city,  the  morning's  milk  is  not  sent 
to  town  until  the  following  morning,  it  being  then  twenty-four 
hours  old. 

As  before  said,  the  various  small  dealers  remove  their  con- 
signments at  once  to  their  dairies,  and  from  this  time  some 
of  this  grade  of  milk  receives  fair  treatment,  being  at  once 
cooled  in  ice-water  and  perhaps  bottled,  ready  for  delivery. 

179 


180  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

In  the  hands  of  less  careful  dealers,  however,  many  further 
accidents  befall  it. 

The  main  delivery  is  made  in  the  morning  following  the 
arrival  of  the  milk  in  town,  when  it  is  from  twenty-four  to 
forty-eight  hours  old;  during  hot  weather  an  extra  delivery 
is  made  at  noon.  As  might  be  expected,  in  summer  weather 
such  a  product  will  necessarily  become  sour  soon  after  delivery, 
and  the  temptation  for  the  small  dealer  to  use  preservatives 
is  in  many  instances  too  great  to  be  resisted. 

The  milk  is  delivered  either  in  the  can  or  in  bottles.  Un- 
fortunately, the  practice  of  ladling  the  milk  from  the  can 
on  the  "  route"  is  still  very  prevalent,  and  it  is  easy  to  imagine 
the  many  additional  means  for  its  contamination  during  this 
process.  The  use  of  bottled  milk  is  becoming  more  popular, 
however,  and  if  the  milk  were  only  pure  to  begin  with,  many 
of  the  dealers  could  be  trusted  to  fulfil  fair  requirements  of 
cleanliness  in  distributing  it.  The  practice  of  filling  bottles 
on  the  wagon,  although  not  the  rule,  is  unfortunately  quite 
common.  The  demand  for  bottled  milk  on  a  particular  route 
may  exceed  the  supply,  and  nothing  is  easier  than  to  fill  some 
of  the  bottles,  returned  by  patrons,  from  the  can,  with  no  fur- 
ther precautions  for  the  cleanliness  of  the  bottles  than  the 
housewife  has  chosen  to  take ! 

It  is  needless  to  comment  on  such  a  practice,  which  has 
probably  given  rise  to  the  principal  objection  made  against 
bottled  milk, — namely,  the  danger  of  contagion  conveyed  by 
the  bottle.  If  the  bottles  are  not  thoroughly  scalded  and 
cleansed  before  refilling,  they  may  thus  prove  to  be  even  more 
dangerous  than  the  large  delivery  can. 

The  use  of  coloring  matter  and  cream  thickener  is  very 
general.  They  do  less  harm,  perhaps,  than  preservatives,  unless 
they  are  added  to  an  ordinary  milk  and  sold  for  cream,  thereby 
cheating  the  customer  out  of  his  rightful  fat  percentage.  An- 
notto,  a  vegetable  product,  is  the  principal  form  of  coloring 
matter  used,  and  a  compound  of  powdered  gelatin  and  boric 


CARE   OF   THE   MILK.  181 

acid,  such  as  Heller's  Cream  Albumin,  gives  to  "cream"  its 
richness  and  consistency. 

From  this  short  account  it  will  readily  be  seen  how  many 
are  the  defects  and  how  serious  may  be  the  dangers  of  the 
city  milk-supply.  In  marked  contrast  to  the  ordinary  supply 
of  milk  is  that  sold  under  the  seal  of  the  various  milk  com- 
missions which  have  been  established  in  many  of  the  larger 
cities. 

Before  describing  certified  milk,  however,  it  will  be  well 
to  give  a  small  part  of  the  overwhelming  evidence  as  to  the 
extent  to  which  milk  may  be  contaminated  with  disease-pro- 
ducing micro-organisms. 

Estes  246  examined  one  hundred  and  eighty-six  specimens 
of  milk  coming  from  all  parts  of  England.  The  bacillus  tuber- 
culosis was  present  in  eleven  cases  (5.3  per  cent.),  doubtful 
in  two  cases.  Pus  was  present  in  forty-seven  cases  (thirty 
per  cent.),  muco-pus  in  seventy-seven  others  (48.7  per  cent.). 
Blood  was  present  in  twenty-four  specimens;  streptococci  in 
seventy-five  per  cent,  of  all  the  cases.  Eighty  per  cent,  of  all 
the  samples  contained  pus,  muco-pus,  or  streptococci,  and  were 
unfit  for  use. 

Additional  instances  of  contamination  with  bacteria  will 
be  found  in  Chapter  VIII. 

William  E.  Stokes  and  GL  Wegefarth,245  investigating 
the  microscopic  appearance  of  milk,  find  that  the  occurrence 
of  garget  or  inflammation  of  the  udder  in  cows  is  not  infre- 
quent, and  that  milk  from  such  animals  contains  many  pus- 
cells  and  organisms  of  suppuration.  The  studies  of  Booker 
and  others  strongly  suggest  that  such  milk  can  cause  various 
forms  of  gastro-enteritis. 

The  microscopic  examination  of  milk  will  often  draw  at- 
tention to  a  condition  which  might  otherwise  escape  notice. 
The  authors  carried  out  three  series  of  investigations : 

(1)  One  hundred  cows  in  the  country  under  improved  hy- 
gienic care. 


182  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

(2)  Fifty  cows  in  the  country  under  poor  hygienic  care. 

(3)  One  hundred  cows  in  the  city,  stall-fed  and  under  poor 
hygienic  care. 

The  milk  from  Series  No.  1  gave  an  average  of  1.1  pus-cells 
to  the  microscopic  field  (one-twelfth  objective)  and  practically 
no  pus  organisms. 

That  from  No.  2  gave  an  average  of  11.3  pus-cells,  and  that 
from  No.  3  gave  an  average  of  19.2  pus-cells,  while  strepto- 
cocci were  present  in  large  numbers. 

The  authors  conclude  that  when  pus-cells  are  found  in 
large  numbers  in  milk  it  should  suggest  a  careful  inspection 
of  the  herd.  The  standard  for  exclusion  must  necessarily  be 
arbitrary,  but  an  average  of  more  than  five  pus-cells  to  the 
field  with  a  one-twelfth  oil  immersion  objective  should  ex- 
clude an  animal  from  the  herd. 

E.  G.  Freeman  179  in  a  recent  article  discusses  briefly  the 
diseases  which  can  be  transmitted  in  milk  and  the  best  means 
to  avoid  contamination.  He  classifies  such  diseases  as  fol- 
lows: 

I.  Those  in  which  the  pathogenic  germs  that  are  introduced 
into  the  milk  are  conveyed  from  the  body  of  the  diseased  cow, 
as  tuberculosis,  anthrax,  foot-and-mouth  disease,  and  acute 
enteritis. 

II.  Those  in  which  germs  gain  entrance  from  some  other 
source  either  during  or  after  milking,  such  as  cholera,  typhoid 
fever,  scarlet  fever,  and  diphtheria. 

III.  Those  caused  by  milk  which  contains  poisonous  agents 
developed  by  bacterial  growth. 

In  all  these  diseases,  except  anthrax,  we  have  very  conclusive 
evidence  that  the  milk-supply  may  be  the  source  of  contagion. 
From  the  study  of  epidemics  so  caused  Freeman  draws  the 
following  lessons: 

I.  Whenever  a  case  of  communicable  infectious  disease  is 
reported,  inquiry  into  the  source  of  the  milk-supply  should  be 
made. 


CARE   OF   THE   MILK.  183 

II.  Milk  traffic  should  be  carried  on  in  houses  separate  from 
the  dwelling-house;  the  dairy  building  should  be  at  least  one 
hundred  feet  from  the  dwelling-house,  barn,  or  privy.  It 
should  be  on  a  higher  level  of  ground  than  any  of  these,  and 
should  have  its  own  pure  water-supply.  All  of  the  work  of 
the  dairy  should  be  done  in  this  dairy  building,  including  the 
cleansing  of  the  pails  and  cans. 

III.  It  should  be  unlawful  for  any  one  who  has  come  in 
contact  with  a  sick  person  (when  the  sickness  is  not  positively 
known  to  be  non-contagious)  to  enter  the  dairy  building  or 
barn  or  to  handle  the  milk. 

IV.  All  employees  connected  with  the  milk  traffic  should  be 
compelled  to  notify  the  authorities  on  the  outbreak  of  any  dis- 
ease in  their  abodes,  and  to  abstain  from  work  until  permission 
to  resume  is  granted  them  by  the  authorities  so  notified. 

V.  Cities  should  accept  milk  only  from  those  dairies  which 
are  regularly  inspected  and  where  all  the  cows  have  been  tested 
with  tuberculin,  and  where  those  which  give  the  characteristic 
reaction  have  been  killed  and  the  premises  disinfected. 

VI.  The  tuberculin  test  should  be  applied  to  all  cattle,  and 
those  which  react  should  be  killed,  the  owner  being  reimbursed 
from  State  funds.  The  premises  on  which  such  tuberculous 
cattle  have  been  kept  should  be  thoroughly  disinfected.  All 
cattle  which  are  brought  into  a  State  should  be  quarantined 
until  the  tuberculin  test  has  been  applied. 

VII.  The  use  of  one  long  trough  for  the  purpose  of  feeding 
many  cattle  should  be  avoided,  since  it  is  a  ready  means  for 
the  conveyance  of  pathogenic  germs  from  one  animal  to  an- 
other. 

Undoubtedly,  the  adoption  of  such  regulations  would  do 
much  to  reduce  the  amount  of  sickness  conveyed  by  germs 
in  milk.  Freeman  does  not  think  that  any  regulations  can 
entirely  eliminate  this  danger.  He  concludes,  therefore,  with 
a  word  of  caution  in  favor  of  the  destruction  of  pathogenic 
germs  by  some  process  of  sterilization. 


184  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

In  this  country  steps  have  been  taken  in  several  of  the  large 
cities  to  provide  a  milk  which  shall  come  up  to  recognized 
standards  of  strength  and  purity.  The  pioneer  attempts  to 
thus  standardize  the  milk-supply  were  made  by  Henry  L. 
Coit,  of  Newark,  New  Jersey. 

Milk  Commissions,  consisting  of  three  or  more  pediatrists, 
now  exist  in  New  York,  Philadelphia,  Baltimore,  Boston,  and 
Buffalo. 

The  Commission  of  the  Philadelphia  Pediatric  Society  has 
established  the  following  requirements: 

"  7.  The  Commission  shall  select  a  bacteriologist,  a  chemist, 
and  a  veterinary  inspector.  The  bacteriologist  shal]  procure 
a  specimen  of  milk  from  the  dairy  or  preferably  from  delivery 
wagons,  at  intervals  to  be  arranged  between  the  Commission 
and  the  dairy,  but  in  no  case  at  a  longer  interval  than  one 
month.  The  exact  time  of  the  procuring  shall  be  without 
previous  notice  to  the  dairy.  He  shall  test  this  milk  for  the 
number  and  nature  of  bacteria  present  in  it,  to  the  extent  which 
the  needs  of  safe  milk  demand.  He  shall  also  make  a  micro- 
scopic examination  of  the  milk  for  pus-cells.  Milk  free  from 
pus  and  injurious  germs  and  not  having  more  than  ten  thou- 
sand germs  of  any  kind  or  kinds  to  the  cubic  centimetre  shall 
be  considered  to  be  up  to  the  required  standard  of  purity. 

"  8.  The  chemist  shall  in  a  similar  manner  procure  and  ex- 
amine the  milk  for  the  percentage  of  proteids,  fat,  sugar, 
mineral  matter,  and  water  present.  He  shall  also  test  its 
chemical  reaction  and  specific  gravity,  and  shall  examine  it 
for  the  presence  of  foreign  coloring  or  other  matters  or  chemi- 
cals added  as  preservatives.  Standard  milk  shall  range  from 
1029  to  1034  specific  gravity,  be  neutral  or  very  faintly  acid 
in  reaction,  contain  not  less  than  from  3.5  to  4.5  per  cent,  pro- 
teids, from  four  to  five  per  cent,  sugar,  and  not  less  than  from 
3.5  to  4.5  per  cent,  fat,  and  shall  be  free  from  all  foreign  con- 
taminating matter  and  from  all  addition  of  chemical  substances 


CARE   OF   THE   MILK.  185 

or  coloring  matters.  Kichness  of  cream  in  fat  shall  be  speci- 
fied, and  shall  vary  not  more  than  one  per  cent,  above  or  below 
the  figures  named  in  selling.  Neither  milk  nor  cream  shall 
have  been  subjected  to  heat  before  the  examination  has  been 
made,  nor  at  any  time  unless  so  announced  to  the  consumer. 

"  9.  The  veterinary  inspector  shall,  at  intervals  equal  to 
those  of  the  bacteriologist  and  chemist,  and  without  previous 
warning  to  the  dairy,  inspect  the  cleanliness  of  the  dairy  in 
general,  the  care  and  cleanliness  observed  in  milking,  the  care 
of  the  various  utensils  employed,  the  nature  and  quality  of  the 
food  used,  and  all  other  matters  of  a  hygienic  nature  bearing 
upon  the  health  of  the  cows  and  the  cleanliness  of  the  milk, 
including  also,  as  far  as  possible,  an  inquiry  into  the  health 
of  the  employees  on  their  farms.  He  shall  also  see  that  the 
cows  are  free  from  tuberculosis  and  other  disease. 

"10.  .  .  .  Any  dairy,  the  milk  of  which  shall  be  found  by 
the  examiners  to  be  up  to  the  standard  of  the  Commission, 
shall  receive  a  certificate  from  the  Commission. 

"11.  In  case  an  examination  shows  the  milk  not  up  to  the 
standard,  the  dairy  may  have  a  re-examination  made  within  a 
week  or  within  a  short  time,  at  the  discretion  of  the  Com- 
mission. 

"13.  The  dealers  to  whom  certificates  have  been  issued  shall 
furnish  milk  to  their  customers  in  glass  bottles,  hermetically 
sealed  in  a  manner  satisfactory  to  the  Commission.  In  addi- 
tion to  the  sealing,  and  as  a  guarantee  to  the  consumer  that 
the  examination  has  been  regularly  conducted,  there  shall  be 
pasted  over  the  mouth  of  the  jar,  or  handed  to  the  consumer 
with  every  jar,  according  to  the  discretion  of  the  Commission, 
a  certificate  slip.  .  .  ." 

The  inspection  and  analysis  of  certified  milk  are  most  thor- 
ough, since  not  only  the  hygienic  cleanliness  of  the  milk  but 
also  the  percentage  of  its  ingredients  must  be  determined. 


186  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

To  insure  a  uniform  standard  in  the  constituents  of  milk, 
careful  selection  of  the  cattle  is  required  and  an  equal  care 
in  their  feeding  and  daily  hygiene.  The  best  breeds  of  cows 
available  for  infant  feeding  in  this  country,  according  to 
Rotch/19  are  the  Durham,  Devon,  Holstein-Friesian,  Ayr- 
shire, Bretonne,  and  Brown  Swiss.  The  red  cows  in  this 
country  do  not  come  up  to  the  standard,  owing  to  their  lia- 
bility to  gastro-intestinal  disorders.  The  famous  Jersey  and 
Guernsey  cows  furnish  a  rich  milk,  but  they  are  more  liable 
to  contract  tuberculosis  (when  transported  from  the  Channel 
Islands  to  a  more  severe  climate)  than  the  breeds  above  men- 
tioned. Some  dairies  require  a  two  months'  quarantine  for 
Jersey  and  Guernsey  cows  before  applying  the  tuberculin  test. 

Rotch  119  declares  that  cows  which  furnish  milk  for  infant 
feeding  should  possess  the  following  characteristics: 

I.  Constitutional  vigor. 

II.  Adaptability  to  acclimatization. 

III.  Notable  ability  to  raise  their  young. 

IV.  Freedom  from  intense  in-breeding. 

V.  Distinct  emulsification  of  the  fat  in  the  milk. 

VI.  A  preponderance  in  the  fats  of  the  fixed  over  the  vola- 
tile glycerides. 

Volatile  glycerides  do  not  exist  in  the  mammae,  but  form  in 
the  milk  soon  after  milking,  especially  in  the  case  of  Jersey  and 
Guernsey  cows. 

Cautley.38  The  failure  of  cow's  milk  to  give  satisfaction 
as  an  artificial  food  may  be  due  to  one  or  more  of  the  follow- 
ing conditions: 

I.  A  faulty  condition  of  the  cow,  such  as  excessive  age,  pro- 
longed lactation,  recent  calving  (the  milk  containing  colos- 
trum corpuscles),  etc. 

II.  Diseases  of  the  cow,  such  as  pneumonia,  foot-and-mouth 
disease,  diseases  of  the  udder,  etc. 

III.  Improper  feeding  and  care  of  the  animal. 

IV.  Improper  or  careless  milking. 


CARE   OF   THE   MILK.  187 

V.  Improper  handling  of  the  milk  before  it  reaches  the  con- 
sumer. 0 

VI.  Improper  composition  of  the  milk,  such  as  deficiency 
in  fat,  etc. 

Monti  "  says :  "  To  get  proper  milk  of  stable  composition 
the  cow  should  have  calved  three  months  previously,  and  only 
the  milk  obtained  during  the  next  four  months  should  be 
used;  after  this  the  milk  contains  too  much  casein  and  too 
little  sugar  and  fat." 

Taylor  and  Wells  147  give  the  third  to  the  ninth  year  of 
the  cow's  life  as  the  best  period  of  lactation. 

Klimmer  85  states  that  the  liability  to  tuberculosis  in- 
creases with  the  age  of  the  cow,  and  that  tuberculosis  is 
especially  prevalent  during  the  best  years  of  lactation. 

Milk  should  not  be  used  until  free  from  colostrum  cor- 
puscles, nor  during  advanced  gestation.  During  the  cata- 
menia  it  is  probably  unfit  for  infant  feeding,  but  this  objec- 
tion scarcely  applies  if  the  mixed  milk  of  the  herd  is  used. 

The  next  most  important  factors  for  the  production  of  clean 
milk  are  the  care  of  the  cow  and  cleanliness  in  the  process  of 
milking. 

Eotch  says  that  the  barn  should  have  a  capacity  of  at  least 
twelve  hundred  cubic  feet  of  air  for  each  cow ;  light  and  venti- 
lation are  essential,  especially  in  the  prevention  of  tuberculosis. 
Whenever  the  weather  permits,  the  cows  should  be  turned  out 
in  the  sunning  yards  when  not  being  milked.  These  yards 
should  drain  away  from  the  barn,  the  water-supply,  and  the 
milk-house.  The  fittings,  troughs,  floor,  etc.,  of  the  barn  should 
be  of  impervious  material  capable  of  being  thoroughly  cleansed 
with  water;  the  floor  should  drain  well  to  remove  excreta. 
The  stall  should  be  wide  enough  to  allow  freedom  of  motion 
for  the  cow.  The  bedding  should  be  fresh  and  free  from 
mould  or  any  soil  productive  of  bacterial  growth.  At  the 
Walker-Gordon  farm  at  Chestnut  Hill,  Pennsylvania,  they  find 
that  shavings  answer  the  purpose  admirably.     Whatever  the 


188  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

material  selected,  it  should  be  changed  before  milking, — twice 
a  day. 

The  cows  should  be  treated  with  a  proper  amount  of  con- 
sideration, especially  before  the  milking  hours.  Fright  and 
unusual  excitement  must  be  avoided,  as  they  are  apt  to  disturb 
lactation  or  may  even  suppress  it.  The  water-supply  for  the 
herd  must  be  above  suspicion;  it  is  best  that  each  cow  have 
a  separate  drinking-trough  in  which  the  water  can  be  renewed 
frequently. 

One  part  nitrogenous  to  five  and  a  half  or  six  parts  non- 
nitrogenous  is  the  proper  ratio  in  the  cow's  fodder  to  produce 
the  milk  best  suited  for  the  infant's  needs.  The  nitrogenous 
elements  are  found  in  clovers,  beans,  peas,  vetches,  wheat 
bran,  etc.,  while  timothy,  rye,  Kentucky-blue,  maize  meal, 
and  oat  straw  represent  the  non-nitrogenous.  In  the  green 
state  most  of  the  grasses  afford  a  fairly  balanced  nutriment, 
but  care  must  be  exercised  in  changing  from  fresh  to  dry 
rations,  owing  to  the  changes  which  this  causes  in  the  compo- 
sition of  the  milk,  thereby  interfering  with  its  proper  diges- 
tion.119 

Plenty  of  food  and  little  exercise  increase  the  yield  of 
milk.38  Nitrogenous  foods  increase  the  fat 38  and  the  casein- 
ogen.52  Carrots  and  beet  roots  increase  the  sugar  of  milk.52 
The  refuse  from  breweries  and  distilleries  makes  milk  abun- 
dant in  quantity  but  deficient  in  solids.  Diseased  potatoes  or 
turnips  give  an  unpleasant  taste  and  smell.52 

Cautley  considers  that,  on  the  whole,  pasture-fed  cows  are 
apt  to  produce  a  milk  better  suited  for  the  infant  than  that  of 
stall-fed  animals.  Grass-fed  cows  are  apt  to  have  alkaline  or 
nearly  alkaline  milk.  Those  fed  in  stalls  on  dry  fodder  and 
grain  usually  give  milk  of  an  acid  reaction.119 

Gordon  has  found  that  Austrian  sugar-beets,  in  the  pro- 
portion of  ten  pounds  daily  per  cow,  as  part  of  the  non- 
nitrogenous  element  of  the  diet,  made  the  milk  neutral  or 
slightly  alkaline.     This  reaction  persisted  for  several  hours  at 


CARE   OF   THE   MILK.  189 

the  ordinary  temperature.  One-third  of  the  milk  from  the 
cows  so  fed,  when  added  to  two-thirds  of  the  mixed  milk  of 
a  herd  fed  on  ordinary  diet,  caused  a  neutral  or  slightly  alka- 
line reaction.119 

In  order  to  obtain  milk  in  an  approximately  sterile  condi- 
tion several  things  are  necessary.  The  cow's  udder,  abdomen, 
flanks,  and  groins  should  be  well  groomed,  and  during  the  hot 
weather  the  hair  should  be  clipped.  In  addition  to  this,  before 
each  milking,  they  should  be  thoroughly  washed,  preferably 
with  a  1  to  1000  bichloride  solution,  and  carefully  dried.  This 
process  should  include  the  teats  as  well.  During  the  summer 
time  particles  of  dirt  fall  into  the  milk-pail  from  the  switching 
of  the  cow's  tail  in  driving  off  the  flies.  Care  should  therefore 
be  taken  to  prevent  as  far  as  possible  the  entrance  of  flies  into 
the  barn,  and  by  the  use  of  narrow-mouthed  milk-pails  to 
avoid  contamination  from  the  air  and  the  sides  of  the  cow. 

The  milkers  should  be  dressed  in  clean  sterile  white  suits 
and  caps.  Their  hands  and  arms  should  be  thoroughly 
scrubbed  and  dried  before  each  milking;  in  some  dairies  the 
use  of  sterilized  cotton  gloves  is  advocated.  No  one  suffering 
from,  or  who  comes  in  contact  with,  any  infectious  disease 
should  be  allowed  to  perform  any  duties  in  connection  with 
the  dairy  farm. 

In  the  milking  process  sufficient  force  should  be  exerted  to 
imitate  suction  by  the  calf,  and  at  each  milking  every  drop 
should  be  withdrawn.  The  first  few  drops  or  streams  should 
always  be  discarded,  so  that  the  milk-ducts  may  be  washed  free 
from  bacteria. 

The  milk-pails  may  be  of  a  variety  of  designs,  but  a  long, 
narrow  pail  offering  a  small  surface  for  air  contamination, 
and  with  rounded  corners  and  edges  to  insure  easy  and  com- 
plete cleansing,  embodies  all  the  essentials.  As  soon  as  the 
pail  is  filled  it  should  be  carried  to  the  milk-house. 

The  following  is  a  description  of  the  milk-house  at  the 
Walker-Gordon  farm  near  Philadelphia. 


190  THE  ARTIFICIAL   FEEDING   OF   INFANTS. 

The  milk-house  is  situated  far  enough  from  the  barn  to  be 
free  from  all  odors.  Its  construction  insures  thorough  ventila- 
tion ;  the  windows  and  doors  are  all  protected  with  fly-screens. 
The  milk-house  is  divided  into  three  rooms, — the  engine-room, 
the  washing-  and  sterilizing-room,  and  the  milk-room  proper. 
The  floors  are  of  concrete  to  allow  of  flushing. 

The  milk-cans,  when  filled,  are  brought  from  the  barn  and 
emptied  into  a  covered  receptacle  set  in  the  wall  of  the  milk- 
room.  This  is  further  protected  from  the  air  and  dust  by  a 
shed;  in  this  shed  are  also  steam  faucets  over  which  the  cans 
are  inverted  and  filled  with  live  steam  before  using  again. 
The  milk  runs  from  this  receptacle  through  a  pipe  in  the  wall 
of  the  milk-room  directly  to  the  aerator  and  cooler,  and  is 
strained  through  eight  thicknesses  of  sterile  gauze  on  the  way. 
This  obviates  the  necessity  for  the  milkers  to  have  access  to  the 
milk-room. 

The  milk  runs  down  from  the  pipe  over  a  corrugated  zinc 
plate  which  is  cooled  by  a  set  of  ice-water  tubes  under  it,  and 
then  drops  into  a  porcelain  tub,  from  which  it  can  be  drawn 
off  and  bottled.  This  aerating  process  reduces  the  tempera- 
ture to  about  60°  F.  The  milk  is  then  bottled,  sealed  with 
sterile  pasteboard  caps,  placed  in  ice-water,  and  kept  at  a  tem- 
perature of  from  45°  to  50°  P.  until  ready  for  delivery. 
During  the  heated  term  the  bottles  are  packed  in  cracked  ice 
before  being  placed  in  the  wagon. 

A  portion  of  the  milk-supply  of  the  Walker-Gordon  plant, 
instead  of  being  bottled,  is  run  through  the  separator  and 
the  cream  shipped  to  town  for  use  in  the  Milk-Laboratory. 
The  morning's  milk  can  be  delivered  within  eight  hours  of 
being  drawn,  the  evening's  product  never  arriving  later  than 
from  twelve  to  eighteen  hours  after  milking. 

When  the  bottles  are  returned  from  the  consumers  they  are 
thoroughly  washed  in  water  containing  soda  and  are  then 
sterilized  with  live  steam  for  thirty  minutes.  The  porcelain 
tub  into  which  the  milk  falls  from  the  aerator  can  also  be  cov- 


CARE   OF   THE   MILK. 


191 


ered  and  sterilized  with  steam.     By  these  means  all  possible 
chances  for  contamination  are  rigorously  excluded. 

The  experiments  of  Peters  119  seem  to  prove  that  a  prac- 
tically sterile  milk  can  be  obtained,  provided  the  proper  pre- 
cautions are  carried  out.  Four  cows  were  used  in  these  ex- 
periments. The  milker  was  dressed  in  a  sterilized  white  suit 
and  cap,  and  his  hands  and  arms  thoroughly  washed  with  a 
1  to  1000  bichloride  solution.  The  cows'  udders,  teats,  flanks, 
sides,  and  abdomens  were  washed  with  the  same  solution  and 
dried  with  a  sterile  towel,  and  the  milk  w^s  received  in  sterile 
bottles. 


No.  of  colonies  of  bacteria' 
per  cubic  centimetre. 

No.  I.     Milk  of  the   first  half  /  D&cei¥ed  by  hand 

directly  into  the  bottle J/.. \.  / 141-167-11-53 

No.  II.     Milk  of  the  first  half  drayn  by  a  sterile 

canula  into  the  bottle  . .,_. . /./. .J\ 0-0-1-2 

Nos.  III.  and  IV.     Drawi/by  hand  after  more  than  (        0-6-0-0 

half  the  udder  had  bee/  emptied/ . .  A. (        0-0-1-2 


The  bacteria  in/N/6.  1  may  hale  come  partly  from  the  air, 
but  most  likely  irom  the  teats,  which  had  become  infected 
through  their  orinees  with  ordinary  forms  of  cocci  and  bacilli. 
The  hands  of  the  milker  may  jijeo  have  carried  infection. 

We  have  taken  as  our  standard  for  the  description  of  what 
the  dairy  farm  should  be  the  works  of  Eotch  and  Cautley  and 
our  own  observation  of  the  Walker-Gordon  farm.  This  shows 
what  is  being  done  in  the  dairies  which  have  accepted  the 
standard  set  by  the  Philadelphia  Milk  Commission.  It  is 
interesting  to  note  that  the  American  standard  for  certified 
milk  is  equal  if  not  superior  to  that  of  any  other  country. 

Certified  milk  will  probably  command  a  higher  price  than 
average  milk,  at  least  for  a  long  time;  but  it  is  not  too  much 


192  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

to  hope  that  with  the  increase  of  competition  the  general 
public  will  eventually  obtain  an  approximately  clean  product 
of  moderate  price  and  infinitely  superior  to  that  which  we 
have  hitherto  been  forced  to  accept. 

In  view  of  the  well-known  excellence  of  the  dairy  products 
of  Denmark  it  is  worth  our  while  to  study  the  method  of 
handling  milk  which  is  carried  out  in  Copenhagen,  Denmark. 

The  milk  is  brought  to  the  company  by  various  farmers, 
and  only  sound  milk  is  received.  By  the  regulations,  the  milk 
of  any  sick  cow  is  paid  for  at  the  regular  rates,  also  the 
wages  of  any  employee  who  is  suffering  from  an  infectious  dis- 
ease. The  milk  is  supplied  to  the  consumer  in  sterilized  bottles 
closed  with  clean  new  corks.  The  company  guarantees  veteri- 
nary control  of  all  cows  from  which  the  milk  is  obtained  and 
the  exclusion  of  that  from  suspected  animals;  also  the  cool- 
ing of  milk  to  40°  F.  or  lower  at  the  farms  and  depots;  also 
the  purification  of  the  total  product  by  upward  filtration 
through  fine  gravel ;  also  absolute  cleanliness  of  all  bottles  and 
cans  which  are  stamped  with  the  company's  seal.  The  cows 
are  inspected  once  every  two  weeks  by  a  veterinary  surgeon, 
and  an  inspector  reports  monthly  on  the  fodder,  state  of  the 
sheds,  and  the  care  exercised  in  the  milking.  During  the 
summer  the  cows  get  fresh  pasture,  grass,  and  clover;  in  the 
winter,  hay,  oats,  bran,  and  carrots. 

The  following  is  an  extract  from  the  regulations: 

"  The  food  of  the  cows  must  be  of  such  a  character  that  no 
bad  taste  or  taint  may  be  imparted  to  the  milk  by  it.  Brewers' 
grains  and  all  similar  refuse  from  distilleries  are  distinctly  for- 
bidden, as  is  also  every  kind  of  fodder  which  is  not  fresh  and 
in  good  condition.  Turnips  and  turnip  leaves  are  strictly 
forbidden.  Carrots  and  mangolds  are  allowed  up  to  one-half 
bushel  for  each  cow,  but  only  when  at  least  seven  pounds  of 
corn,  bran,  and  cake  are  also  given.  Eape-seed  cake  is  the  only 
oil-cake  which  may  be  used.  Stall  feeding  in  summer  is  not 
allowed  under  any  circumstances.     Cows  must  be  fed  in  the 


CARE   OF   THE   MILK.  193 

open  air  on  grass  and  clover.  Vetches  are  forbidden.  In  the 
autumn  the  cows  must  be  clipped  on  the  udder,  tail,  and  hind 
quarters  before  being  taken  in.  The  milk  of  cows  newly  calved 
must  be  withheld  for  at  least  twelve  days,  and  must  be  not 
less  in  quantity  than  three  quarts  a  day.  Immediately  after 
milking,  in  all  seasons,  the  milk  must  be  cooled  to  40°  F.  in 
ice-water." 

George  T.  Palmer,217  in  the  Philadelphia  Medical  Journal, 
describes  the  Trinity  Diet  Kitchen  which  has  been  established 
in  Chicago  to  supply  a  pure,  modified,  unheated  cow's  milk  for 
infants  in  the  poor  district. 

The  milk  is  obtained  from  the  farm  of  H.  B.  Gurler,  of 
De  Kalb,  Illinois.  Much  the  same  precautions  as  those  de- 
scribed by  Eotch  in  relation  to  Laboratory  Milk  are  employed 
on  this  farm.  The  cattle  are  mainly  of  Holstein  breed,  tuber- 
culin tested,  and  carefully  fed.  Any  cow  which  becomes  sick  is 
at  once  isolated  from  the  herd  in  a  separate  building,  etc.  By 
a  rapid  process  of  cooling  within  from  ten  to  twelve  minutes 
after  milking  the  temperature  of  the  milk  is  reduced  to 
45°  F.,  and  within  twenty  minutes  after  milking  it  has  been 
bottled  and  sealed.  Such  milk  has  been  kept  on  ice  in  the 
Diet  Kitchen  for  almost  two  weeks  without  souring.  Not  one 
ounce  of  either  sterilized  or  pasteurized  milk  has  ever  been 
distributed  from  this  Diet  Kitchen.  A  plentiful  supply  of 
ice  with  each  bottle,  and  rigid  instructions  to  the  parents 
with  regard  to  absolute  cleanliness  in  handling  the  milk,  keep- 
ing it  cold,  and  regularity  in  feeding,  contributed  largely  to 
the  good  results  obtained. 

The  following  account  of  milk  inspection  as  carried  out 
by  the  New  York  Board  of  Health  is  given  by  Herman 
Betz  202  in  the  Medical  News  for  March  10,  1900. 

The  inspection  is  carried  out  by  a  corps  of  "  milk  inspectors" 
who  make  visits  at  short  intervals  to  all  of  the  dairies  in  their 
respective  districts.  If  the  milk  prove  unsatisfactory  by  the 
lactometer  and  thermometer  tests,  a  sample  is  taken  for  analy- 

13 


194  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

sis.  This  analysis  includes  the  determination  of  (a)  the  per- 
centage of  water,  (&)  the  total  solids,  (c)  the  fat,  (d)  the 
solids  not  fat,  (e)  the  percentage  low  in  solids,  (/)  the  per- 
centage low  in  fat,  (g)  the  reaction,  and  (h)  the  presence  of 
preservatives,  such  as  borax,  salicylic  acid,  or  formaldehyde. 
The  retail  dealer  does  not  receive  his  permit  until  the  inspector 
has  satisfied  himself  that  the  shop  and  premises  are  in  satis- 
factory condition,  and  that  hygienic  cleanliness  of  the  appli- 
ances has  been  obtained.  If  the  dealer  fails  to  maintain 
hygienic  precautions,  or  if  the  milk  analysis  shows  that  it  is 
more  than  five  per  cent,  low  in  solids  or  three  per  cent,  low  in 
fat,  or  contains  preservatives,  the  permit  for  its  sale  is  either 
withheld  or  withdrawn  until  the  requirements  are  met. 

The  wholesale  dealer  is  required  to  give  a  list  of  the  farms 
from  which  he  obtains  his  supply,  the  breeds  of  cows  employed, 
the  precautions  used  in  handling  the  milk,  and  the  railroads 
on  which  it  is  shipped.  In  case  of  an  epidemic  of  sickness 
occurring  in  any  of  the  towns  from  which  New  York  draws  its 
milk-supply,  notification  is  made  to  the  Board  of  Health,  and 
that  portion  of  the  supply,  if  in  any  way  liable  to  infection, 
can  be  stopped.  Each  wagon  of  the  wholesale  dealer  is  re- 
quired to  have  a  separate  permit,  and  the  name  and  address 
of  the  driver  is  kept  on  file.  Each  permit,  in  store  or  wagon, 
must  occupy  a  conspicuous  place. 

Edward  B.  Voorhees,  in  a  Eeport  on  Food  and  Nutrition 
Investigations  (abstract  in  the  Dietetic  and  Hygienic  Gazette, 
No.  13,  1897),  asserts  that  the  price  of  milk  should  be  gov- 
erned by  its  fat  content.  It  is  entirely  practicable,  under 
present  conditions,  for  even  the  smaller  producers  and  dealers 
to  guarantee  a  product  containing  a  reasonably  definite  quan- 
tity of  fat,  because  the  chief  causes  of  variations  in  the  quality 
of  the  milk  are  well  known,  and  inexpensive  instruments,  sim- 
ple in  operation,  are  available  for  testing  its  fat  content. 

Huddleston.72  The  two  kinds  of  cream  furnished  in  New 
York  City  are  gravity,  hand-skimmed  or  Cooley  cream,  and 


CARE   OF  THE   MILK.  195 

machine-skimmed  or  separated  cream.  The  former  has  an 
average  fat  percentage  of  from  twelve  to  sixteen;  it  is  raised 
in  Cooley  cans  to  allow  of  drawing  off  the  milk  from  below 
after  it  has  been  submerged  in  cold  water  for  twenty-four 
hours.  It  is  said  to  keep  poorly,  and  a  compound  of  borax 
and  salicylic  acid  called  "  Preservitas"  is  often  added  thereto. 
Machine-skimmed  cream  or  separated  cream  is  quickly  pre- 
pared and  keeps  well.  Most  cream  is  at  least  seventy-two 
hours  old  before  it  reaches  the  city.  A  surplus  supply  is  often 
kept  buried  in  ice  for  a  considerable  period.  Certain  dairies, 
however,  send  cream  to  the  cities  bottled  and  sealed  while 
fresh.  Cream  thickens  with  age;  during  periods  of  cold 
weather  it  is  a  common  practice  to  hold  it  back  so  that  it 
may  appear  richer.  This  increase  in  density  is  due  to  the 
multiplication  of  bacteria. 

Huddleston  advocates  the  selling  of  milk  and  cream  of  known 
guaranteed  fat  percentages,  and  can  find  no  reason  why  dealers 
should  not  supply  cream  as  fresh  as  milk.  Pasteurization 
can  be  practised  at  small  cost  at  the  dairy. 


CHAPTER   VIII. 
BACTERIOLOGY. 

That  milk  will  sour  if  exposed  to  the  air  for  a  certain 
length  of  time  is  a  fact  so  well  known  that  it  scarcely  needs 
repetition,  but  it  is  only  within  recent  years  that  we  have  been 
able  definitely  to  determine  the  causative  agents  of  this  acidi- 
fication,— namely,  certain  species  of  bacteria.  We  know  also 
that  the  clots  formed  in  this  process  will  under  certain  con- 
ditions redissolve  as  the  result  of  bacterial  action.  It  is 
probable  that  further  changes  in  milk  occur  from  the  pres- 
ence of  micro-organisms,  but  our  knowledge  on  this  subject  is 
still  in  its  infancy.  At  least  we  know  that  many  of  the  prod- 
ucts resulting  from  the  presence  of  acid-producing  bacteria 
in  milk  are  distinctly  harmful  to  the  infant  organism.  While 
it  is  possible  that  some  species  of  bacteria  may  be  of  service 
in  preparing  milk  for  the  chemical  changes  it  must  undergo 
before  it  is  ready  for  absorption,  on  the  whole  the  harmful 
far  exceed  the  helpful  varieties  of  milk  bacteria.  It  is  fair, 
then,  to  assume  that  the  freer  a  milk  is  from  micro-organisms 
the  more  suitable  it  will  be  for  the  needs  of  the  infant. 

It  is  of  course  true  that  sterile  milk  becomes  infected  with 
bacteria  as  soon  as  it  enters  the  mouth  and  the  gastro-intestinal 
tract.  When  there  is  digestive  disturbance,  however,  we  will 
have  reduced  the  etiological  factors  of  disease  by  a  very  im- 
portant item  if  we  are  able  to  exclude  contamination  of  the 
milk-supply. 

It  must  not  be  forgotten,  in  dealing  with  a  milk  which  has 
well  matured,  that  the  ordinary  methods  of  sterilization  will 
destroy  the  group  of  lactic  acid  bacteria  and  leave  the  proteo- 
lytic or  peptonizing  group  unharmed,  and  that  toxic  products 
may  result  from  the  presence  of  excessive  numbers  of  pep- 
196 


BACTERIOLOGY.  197 

tonizing  bacteria.  Since  these  two  groups  are  naturally  an- 
tagonistic, it  may  prove  a  questionable  advantage  to  overthrow 
the  balance  between  them.  This  in  no  wise  changes  the  origi- 
nal dictum  that  milk  should  have  a  low  bacterial  content  to 
be  an  ideal  food  for  infants.  Such  milk  requires  no  other 
preservative  than  a  low  temperature,  and  no  objection  has  yet 
been  offered  to  its  use. 

In  the  following  pages  we  shall  attempt  to  give  a  brief  out- 
line of  what  has  been  done  in  that  branch  of  bacteriology  which 
concerns  itself  with  the  micro-organisms  found  in  milk. 

Bacteria  are  found  in  the  meconium  within  four  hours  after 
birth,  from  infection  through  the  rectal  orifice;  somewhat 
later  they  gain  entrance  to  the  mouth  from  the  air,  bathing 
water,  etc.7 

S chill  (Zeitschrift  fur  Hygiene  und  Infect.  Krankheiten, 
Bd.  xix.,  1895)  and  von  Puteren  (quoted  by  Mannaberg  in 
his  work  on  Intestinal  Bacteria,  Vienna,  1895)  consider  that 
no  amount  of  sterilizing  can  prevent  the  entrance  of  bacteria 
into  milk  faeces,  even  when  the  milk  does  not  contain  them. 
Infection  probably  comes  from  the  swallowing  of  saliva.  Lan- 
germann  and  Eberle  have  shown  that  almost  sterile  food  will 
become  infected  through  the  stomach  and  intestines. 

Langermann  found  that  the  infant's  stomach  normally  con- 
tained from  3700  to  240,000  bacteria,  in  nursing  children  from 
6960  to  20,000,  in  the  sick  incomparably  more,  and,  even  in 
the  presence  of  free  hydrochloric  acid,  there  were  from  3200 
to  6400.  Free  hydrochloric  acid  is  not  found  constantly  in 
the  infant's  stomach ;  it  can  serve  only  to  diminish  and  not  to 
suppress  bacterial  growth  (Jahrbuch  fur  Kinderkrankheiten, 
Bd.  xxxv.). 

Eberle  counted  33,000,000  micro-organisms  in  one  milli- 
gramme of  fresh  faeces  (only  1,500,000  to  3,000,000  by  cul- 
ture), even  when  sterile  food  was  used  (Centralblatt  fur 
Bacteriologie  und  Parisitenkunde,  Bd.  xix.,  1896). 

Miquel  105  has  estimated  the  rapidity  with  which  bacteria 


198  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

multiply  in  cow's  milk.  The  specimen  contained  9000  bac- 
teria in  each  cubic  centimetre  on  its  arrival  at  the  laboratory 
two  hours  after  milking. 

One  hour  later  it  contained 21,750 

Two  hours  later  it  contained 36,250 

Seven  hours  later  it  contained 60,000 

Nine  hours  later  it  contained 120,000 

Twenty-five  hours  later  it  contained 5,600,000 

Heat  favors  the  multiplication  of  bacteria.  In  the  same 
milk,  after  fifteen  hours'  exposure  at  15°  C,  Miquel  found 
100,000  bacteria  per  cubic  centimetre,  while  at  25°  C.  there 
were  72,000,000,  and  at  35°  C.  165,000,000. 

Sedgewick  and  Batchelder,69  in  Boston  in  1892,  found  an 
average  number  of  70,000  bacteria  per  cubic  centimetre  of  milk 
handled  in  the  usual  way  and  examined  a  few  hours  after  milk- 
ing. In  fifty-seven  samples  of  milk  taken  from  the  ordinary 
delivery  wagons  they  found  an  average  of  2,355,000  bacteria. 

Backhaus's  investigations  85  show  to  what  extent  different 
factors  contribute  in  influencing  the  bacterial  contamination 
of  milk. 

Milking. 

Dry  milking 5,600  germs  per  cubic  centimetre 

Wet  milking 9,000  germs  per  cubic  centimetre 

First  milk 10,400  germs  per  cubic  centimetre 

Last  milk Sterile 

Care  of  the  Cow. 

When  the  cow  is  cleaned 20,600  germs  per  cubic  centimetre 

When  the  cow  is  not  cleaned 170,000  germs  per  cubic  centimetre 

Udder  washed 2,200  germs  per  cubic  centimetre 

Udder  not  washed 3,800  germs  per  cubic  centimetre 

Air  Contamination. 
If  the  cow  is  milked  in  the  open  air. .         7,500  germs  per  cubic  centimetre 
If  the  cow  is  milked  in  a  clean  stall. .       29,250  germs  per  cubic  centimetre 
If  the  cow  is  milked  in  an  unclean  stall      69,000  germs  per  cubic  centimetre 


BACTERIOLOGY.  199 

Vessels  used. 

Enamelled  vessels 1,105  germs  per  cubic  centimetre 

Tin  vessels 1,690  germs  per  cubic  centimetre 

Wooden  vessels 279,000  germs  per  cubic  centimetre 

Clean   Vessels. 

Sterilized  vessels 1,300  germs  per  cubic  centimetre 

Washed  vessels 28,600  germs  per  cubic  centimetre 

Infection. 

Fresh  milk 6,660  germs  per  cubic  centimetre 

Milk  passed  through  six  vessels 97,600  germs  per  cubic  centimetre 

Straw. 

Turf  . . . . 40,000  germs  per  cubic  centimetre 

Good  straw 150,000  germs  per  cubic  centimetre 

Dirty  straw 200,000  germs  per  cubic  centimetre 

Water. 

Fresh  water 322  germs  per  cubic  centimetre 

Trough  water.. 228,200  germs  per  cubic  centimetre 

Milk  supplied  from  a  good  dairy  farm      25,000  germs  per  cubic  centimetre 
Milk    supplied    to    the     Konigsberg 
market 2,000,000  germs  per  cubic  centimetre 

Cautley.38  Human  milk  is  usually  considered  sterile  when 
there  is  no  local  disease  of  the  breast.  This  is  doubtless  true 
of  the  milk  contained  in  the  gland.  Escherieh  found  the  milk 
of  twenty-five  healthy  women  absolutely  devoid  of  micro-organ- 
isms. On  the  other  hand,  Cohn  and  Neumann  found  microbes 
in  the  milk  of  forty-three  out  of  forty-eight  healthy  women. 
The  varieties  of  organisms  most  commonly  present  were  the 
staphylococcus  pyogenes,  albus  and  aureus,  and  the  strepto- 
coccus pyogenes.  Honigmann  made  seventy-six  examinations 
of  the  milk  of  sixty-four  women,  recently  confined,  and  found 
it  sterile  on  four  occasions  only.  Ringel  examined  the  milk 
of  twelve  healthy  and  thirteen  ill  nursing  women,  and  found 


200  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

it  sterile  in  three  only.  The  microbes  are  most  numerous  in 
the  milk  first  secreted,  and  in  all  probability  have  made  their 
way  along  the  ducts  in  the  nipple.  The  milk  last  poured  out 
is  quite  sterile. 

Marfan.105  We  may  safely  conclude  that  the  milk  of 
healthy  mothers,  obtained  under  aseptic  precautions,  contains 
micro-organisms  nineteen  times  out  of  twenty.  These  are  usu- 
ally the  staphylococcus  albus  or  aureus  (Honigmann,  Paleske, 
Ringel,  Knochenstirn,  Genoud,  Charrin,  Trinci).  These  in- 
vestigators are  agreed  in  recognizing  that  only  the  first  por- 
tions of  the  milk  obtained  contain  micro-organisms,  and  that 
these  organisms  are  found  only  at  or  near  the  orifices  of  the 
lactiferous  channels  and  not  in  the  depth  of  the  gland;  hence 
they  are  not  the  result  of  elimination  by  the  mammary  gland. 
They  come  either  from  the  skin  near  the  orifices  in  the  nipple 
or  from  the  infant's  mouth. 

These  remarks  as  to  the  frequency  of  infection  of  woman's 
milk  through  the  nipples  apply  equally  well  to  cow's  milk, 
only  in  the  latter  case  the  liability  to  infection  is  even  greater. 
Lehmann  and  Schultz  were  among  the  first  to  demonstrate  that 
cow's  milk  is  practically  never  sterile. 

The  microbes  which  are  found  in  cow's  milk  ordinarily  gain 
entrance  in  one  of  the  two  following  ways:  most  often  they 
are  introduced  during  the  act  of  milking  and  the  manipulations 
following  it;  less  commonly  the  milk  is  rendered  virulent  by 
the  presence  of  the  germs  of  an  infectious  disease  from  which 
the  cow  is  suffering.  The  first  are  the  ordinary  saprophytic 
germs  which  are  universally  distributed  throughout  nature  and 
are  not  pathogenic;  but  they  spoil  milk  and  render  it  more 
or  less  toxic.  Exceptionally,  accidental  infection  of  milk  with 
pathogenic  germs  may  occur. 

The  Saprophytic  Microbes  of  Milk.105 
Apart  from  infection  of  milk  by  organisms  which  make  their 
way  into  the  ducts  of  the  nipple  (which  is  of  minor  importance) . 


BACTERIOLOGY.  201 

there  are  many  fruitful  sources  for  its  further  contamination. 
Soxhlet  has  isolated,  in  cow's  milk,  the  following  impurities: 
faeces,  dust,  and  particles  of  hay,  grass,  and  straw.  Infection 
may  also  occur  from  the  hands  or  person  of  the  milker,  from 
particles  of  dirt,  hairs,  etc.,  brushed  from  the  animal's  flanks 
and  udder,  and  from  the  receptacles  into  which  the  milk  is 
drawn.  Substances  added  to  milk,  such  as  water,  coloring 
matter,  etc.,  may  lead  to  infection.  Marfan  considers  that 
infection  from  the  air  is  of  less  importance  than  was  formerly 
thought. 

Lactic  Acid  Bacteria™* 

The  most  frequent  modification  which  milk  undergoes  is 
lactic  acid  fermentation.  If  fresh  milk  is  allowed  to  stand, 
it  first  becomes  acid  in  reaction  and  of  a  bitter  taste.  At  the 
end  of  a  period  varying  from  one  to  four  days,  according  to 
the  temperature,  coagulation  occurs.  This  is  due  to  the  trans- 
formation of  the  lactose  into  lactic  acid;  from  seven  to  eight 
per  cent,  of  the  latter  is  sufficient  to  coagulate  the  casein. 
When  milk  is  heated,  a  smaller  quantity  of  lactic  acid  is  re- 
quired for  its  coagulation. 

Pasteur  ascribed  the  transformation  of  lactose  into  lactic 
acid  to  the  activity  of  a  microbe  which  he  called  the  "  lactic 
ferment."  This  seems  to  be  identical  with  the  organism  de- 
scribed by  Hiippe  as  the  "  bacillus  of  lactic  acid." 

Leudet  and  Wurtz  have  established  the  identity  of  the  "  lac- 
tic ferment"  with  the  bacillus  lactis  aerogenes  of  Escherich, 
and  this,  in  turn,  is  closely  allied  to  the  bacillus  coli  communis 
of  Escherich,  which  also  causes  lactic  acid  fermentation. 

Marfan  considers  that  the  usual  lactic  ferments  probably 
represent  different  varieties  of  the  bacillus  coli  communis 
which  are  normally  found  in  the  intestine.  Ordinarily  they 
are  saprophytic,  but  under  certain  conditions  they  may  become 
pathogenic. 

Freudenreich  has  collected  the  following  list  of  organisms 
which  cause  lactic  acid  fermentation:    the  bacterium  acidi 


202  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

lactici  of  Grotenfeld;  the  micrococcus  lactis  I  and  II  of 
Hiippe,  the  micrococcus  acidi  lactici  of  Marpmann,  the  strepto- 
coccus acidi  lactici  of  Marpmann,  the  micrococcus  acidi  lactici 
of  Kriiger,  the  streptococcus  acidi  lactici  of  Grotenfeld,  and  the 
bacillus  prodigiosus. 

Certain  pathogenic  bacteria  can  acidify  and  coagulate  milk : 
the  staphylococcus  pyogenes,  the  pneumococcus  of  Talamon 
and  Frankel,  the  micrococcus  of  contagious  mammitis  of  the 
cow  (Nocard  and  Mollereau),  the  micrococcus  of  gangrenous 
mammitis  of  sheep  (Nocard),  and  the  cholera  bacillus  (Netter, 
de  Hann,  A.  C.  Huysse).  The  streptococcus  of  erysipelas 
acidifies  milk  without  coagulating  it  (Loffler). 

In  the  Twelfth  Annual  Eeport  of  Storr's  Agricultural  Ex- 
periment Station,  Connecticut  (1899),  H.  W.  Conn  has  pub- 
lished a  "  Classification  of  Dairy  Bacteria"  which  comprises 
the  results  of  his  investigations  for  the  past  ten  years.  Over 
two  hundred  different  types  of  bacteria  have  been  found  which 
may  be  regarded  as  more  or  less  distinct  from  one  another. 
In  his  description  he  has  followed  as  closely  as  possible  the 
method  adopted  by  Fuller  and  Johnson  in  their  recent  pub- 
lication on  water  bacteria,  and  has  thereby  endeavored  to 
establish  a  uniform  system  of  classification  which  shall  serve 
as  a  basis  for  bringing  together  the  work  of  American  dairy 
bacteriologists.  The  need  for  such  a  system  can  scarcely  be 
overestimated,  as  without  a  standard  for  comparison  the  work 
of  many  individual  observers  must  go  for  naught. 

Conn  concludes  that  the  dairy  organisms  of  New  England 
are  chiefly  of  four  species,  or,  more  strictly,  three  groups  of 
closely  related  bacteria,  namely, — 

The  bacterium  acidi  lactici  of  Esten.  This  variety  is  very 
generally  found  in  samples  of  milk  and  cream  from  a  wide 
area  of  territory.  In  sour  milk  it  is  almost  always  present. 
Its  frequent  occurrence  in  milk,  together  with  its  markedly 
anaerobic  character,  would  seem  to  indicate  that  it  probably 
comes  from  the  milk-ducts.    Conn's  recent  experiments  (draw- 


BACTERIOLOGY.  203 

ing  the  milk  directly  from  the  teats  into  sterilized  vessels, 
with  little  or  no  chance  for  contamination)  seem,  however, 
to  point  to  the  conclusion  that  this  organism  comes  from 
external  contamination. 

The  variety  of  micro-organism  next  in  frequency  is  No.  202 
on  the  list.  This  species  differs  only  slightly  from  the  bac- 
terium acidi  lactici,  and  the  two  species  undoubtedly  belong 
together.  They  represent  a  type  of  dairy  organism  common 
everywhere.  Many  of  the  lactic  acid  organisms  hitherto  de- 
scribed by  different  bacteriologists  clearly  belong  to  this  type, 
although  slight  differences  in  described  characteristics  perhaps 
indicate  different  varieties.  This  is  true  of  the  bacterium 
acidi  lactici  of  Gunther  and  Thierfelder,  bacterium  lactis  acidi 
of  Leichmann,  bacillus  XIX  of  Adametz,  bacillus  a  of  von 
Freudenreich,  micrococcus  acidi  laevolactici  and  bacillus  acidi 
laevolactici  of  Leichmann,  and  several  types  described  by 
Storch. 

The  next  most  important  dairy  species  described  by  Conn  is 
No.  208,  which  he  regards  as  identical  with  the  bacillus  lactis 
aerogenes.  This  is  found  almost  universally,  although  never 
in  very  great  numbers.  It  is  quite  possible  that  a  number  of 
distinct  types  are  included  under  this  head,  as  the  organisms 
have  shown  wide  variations.  The  distinctive  characteristics 
of  these  species  are:  (1)  the  intense  acid  produced  in  litmus 
gelatin;  (2)  the  abundant  production  of  gas  in  milk-sugar, 
bouillon,  or  milk;  (3)  the  uncertainty  as  to  their  power  of 
curdling  milk,  this  occurring  commonly  at  high  temperatures, 
though  not  at  the  temperature  of  the  room;  and  (4)  the 
distinctive  odor  of  sour  milk  which  they  produce  after  cur- 
dling. 

According  to  Conn's  observations,  ordinary  sour  milk  is  pro- 
duced by  the  three  organisms  mentioned,  and  probably  in  the 
spontaneous  souring  of  milk  all  three  are  present. 

It  is  probable  that  there  belong  to  this  group  also  the  origi- 
nal bacillus  acidi  lactici  of  Hiippe,  the  bacterium  lactis  acidi 


204  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

of  Marpmann,  the  bacillus  acidi  lactici  I  and  II  of  Grotenfeld, 
No.  8  of  Eckels,  and  doubtless  several  others. 

Finally,  Conn  describes  the  micrococcus  lactis  varians.  This 
species  is  common  in  fresh  milk  and  probably  exists  in  the 
milk-ducts.  It  is  often  overgrown  by  the  lactic  organisms  and 
is  less  often  found  in  old  milk. 

Peptonizing  Bacteria. 

105  rj-ij^  ferments  of  casein  or  peptonizing  bacteria  are  sapro- 
phytes belonging  to  the  groups  of  which  the  bacillus  subtilis 
and  bacillus  mesentericus  vulgatus  are  the  prototypes.  These 
microbes  act  on  casein  through  the  products  which  they  secrete. 
They  coagulate  casein  without  acidifying  the  milk  by  the  aid 
of  a  ferment  resembling  lab,  and  they  liquefy  the  coagulum 
and  peptonize  it  by  means  of  a  ferment  called  "  casease"  ( Du- 
claux).  The  peptone  resulting  from  this  is  called  "caseone." 
It  is  only  at  the  end  of  lactic  acid  fermentation  that  the  activity 
of  the  peptonizing  bacteria  begins. 

The  ferments  of  casein  comprise  several  species  of  microbes, 
of  which  the  most  important  are  the  bacillus  subtilis  (hay 
bacillus),  the  bacillus  mesentericus  vulgatus  (potato  bacillus), 
and  the  tyrothrix  group.  The  bacillus  subtilis  and  the  bacillus 
mesentericus  vulgatus  are  aerobic  organisms  and  universally 
distributed.  These  two  species  are  poorly  defined  and  many 
varieties  can  be  included  among  them.  The  characteristics  of 
these  ferments  are,  that  they  utilize  the  casein  after  the  first 
steps  of  digestion  have  rendered  it  assimilable,  and  transform 
it  into  various  products  which  are  found  wherever  microbes 
are  acting  upon  albuminoids, — namely,  leucin,  tyrosin,  urea, 
ammonium  carbonate,  acids  of  the  fatty  acid  series  (formic, 
acetic,  propionic,  butyric,  valeric),  ammonia  and  ammoniacal 
compounds,  carbonic  acid,  water,  hydrocarbon  gases,  hydrogen, 
and  nitrogen. 

Nearly  all  the  peptonizing  bacteria  produce  spores  which 
can  resist  temperatures  higher  than  100°   C.      Fliigge  and 


BACTERIOLOGY.  205 

Liibbert  have  utilized  this  property  for  the  isolation  and  study 
of  the  peptonizing  bacteria,  several  varieties  of  which  they 
have  proved  to  be  pathogenic.  Lesage  has  also  encountered 
in  fermented  milk  a  bacillus  mesentericus  with  pathogenic 
properties. 

The  bacillus  subtilis  and  bacillus  mesentericus  vulgatus  are, 
as  a  rule,  not  found  in  the  faeces  of  the  breast-fed  infant.  When 
they  are  present,  they  are  not  numerous  unless  digestive  trou- 
bles exist;   usually  they  are  not  virulent  (Marfan). 

Flugge.199  Enormous  numbers  of  peptonizing  bacteria  can 
be  present  in  a  milk  which  is  apparently  normal  and  free  from 
germs.  Flugge  asserts  that  the  peptonizing  and  the  most  re- 
sistant anaerobic  bacteria  are  not  destroyed,  though  subjected 
to  a  temperature  of  100°  C.  for  three-quarters  of  an  hour. 
If  such  a  milk  is  kept  for  several  days  at  a  temperature  ex- 
ceeding 22°  C.  (72°  F.),  or  for  a  few  hours  at  a  temperature 
above  26°  C.  (79°  F.),  these  bacteria  will  grow  much  more 
luxuriantly  than  in  unheated  milk,  since  in  the  latter  the 
excessive  number  of  lactic  acid  bacteria  will  hinder  the  develop- 
ment of  other  forms. 

Klimmer  251  states  that  peptonizing  bacteria  are  usually  in- 
troduced into  milk  with  dirt  (dried  faeces).  They  are  among 
the  chief  causes  of  summer  diarrhoea  of  infants. 

Duclaux  230  calls  attention  to  the  fact  that  peptones  are  the 
normal  product  of  digestion,  and  that  countless  millions  of 
peptonizing  bacteria  are  normally  present  in  the  intestines. 
Therefore  it  would  seem  questionable  whether  the  addition  of 
a  few  more  would  make  any  material  difference.  He  thinks 
that  the  harm  resulting  from  their  presence  has  probably  been 
overrated. 

Weber  182  has  made  a  very  thorough  study  of  the  effect  of 
sterilization  on  the  bacterial  content  of  milk.  He  emphasizes 
the  antagonism  between  the  lactic  acid  and  the  peptonizing 
bacteria,  and  points  to  a  possible  danger  from  the  use  of 
the  sterilized  product.    His  conclusions  are  as  follows : 


206  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

I.  The  methods  of  sterilization  of  milk  in  use  at  the  present 
time  are  not  sufficient  to  give  us  with  absolute  certainty  a  germ- 
free  milk.  The  so-called  sterilized  milk  of  the  different  dairies 
has  a  varying  bacterial  content.  The  higher  the  percentage 
of  negative  tests  for  bacteria  the  greater  are  the  alterations 
brought  about  by  the  process  which  are  already  visible  to  the 
naked  eye. 

II.  The  anaerobic  bacteria  play  no  considerable  role  in 
commercial  sterilized  milk,  so  far  as  these  tests  showed. 

III.  Of  the  aerobic  bacteria  the  thermophile  are  of  no  great 
practical  importance,  on  account  of  their  faculty  of  growing 
only  at  high  temperatures.  On  the  other  hand,  they  may  lead 
to  errors  in  bacteriological  investigations,  since  milk  decom- 
posed by  them  will,  when  tested  by  culture  experiments,  seem 
apparently  germ-free. 

IV.  The  aerobic  bacteria  isolated  from  sterilized  milk  all 
have  the  property  of  peptonizing  casein. 

V.  Apart  from  the  group  of  thermophiles  we  can  distinguish 
three  groups  of  aerobic  peptonizing  bacteria,  namely, — 

(a)  Bacteria  which  decompose  the  milk  rapidly  within  from  twenty- 
four  to  forty-eight  hours.  Most  of  them  grow  well  at  room  temperature. 
Most  of  them  peptonize  the  casein  without  attacking  the  milk-sugar ;  but 
some  are  also  capable  of  breaking  up  the  lactose  with  the  formation  of 
strong  acid. 

(6)  Bacteria  which  under  the  most  favorable  conditions  decompose  the 
milk  only  after  five  to  seven  days,  usually  when  the  reaction  is  weakly 
acid  or  amphoteric.  Nearly  all  of  them  grow  best  at  high  temperatures, 
as  well  at  37°  as  at  50°  C.     One  species  grew  well  at  60°  C.     ■ 

(c)  Bacteria  which  do  not  alter  the  appearance  of  the  milk,  although 
they  grow  well. 

VI.  A  number  of  these  peptonizing  bacteria  can  cause  putre- 
factive decomposition  of  cow's  milk  (sterilized)  and  form  in 
this  process  sulphuretted  hydrogen.  Previous  to  its  formation 
the  casein  must  be  peptonized. 

VII.  Lactose  serves  to  check  putrefaction  in  milk  in  so  far 


BACTERIOLOGY.  207 

as  it  favors  the  development  of  acid-producing  bacilli  which 
suppress  the  activity  of  the  peptonizing  bacteria.  This  peculi- 
arity of  lactose  is  fully  developed  in  raw  milk.  On  the  other 
hand,  in  milk  which  has  been  heated  and  so  freed  from  the 
real  acid-forming  bacteria,  this  property  is  not  in  evidence  or 
only  to  a  very  limited  degree.  Consequently  in  heated  milk 
bacteria  develop  which  are  not  found  in  raw  milk,  and  which 
cause  putrefactive  decomposition  of  the  milk.  The  use  of 
so-called  sterilized  milk  (commercial)  for  infant  feeding  would 
seem,  then,  to  be  not  without  danger,  since  the  bacterial  flora 
present  in  this  product  favor  the  occurrence  of  putrefactive 
changes. 

VIII.  The  so-called  *  toxic"  peptonizing  bacteria  of  Fliigge 
also  occur  in  commercial  sterilized  milk,  but  not  very  frequently. 
Only  three  out  of  one  hundred  and  fifty  tests  showed  the  pres- 
ence of  these  bacilli.  Their  mode  of  growth  places  them  in 
the  group  of  hay  bacilli.  They  are  remarkable  for  their  ability 
to  decompose  albuminous  substances  and  to  form  sulphuretted 
hydrogen.  In  this  peptonizing  power  seems  to  lie  the  chief 
danger  for  the  infant  organism. 

Kalischer  204  experimented  with  one  variety  of  pepto- 
nizing bacteria  and  found  that  they  produced  a  soluble  ferment 
capable  of  inverting  cane-sugar  but  not  milk-sugar.  They  did 
not  attack  the  fat,  and  there  was  no  evidence  of  diastatic 
fermentation.  They  form  from  casein,  albumose,  and  later 
peptone,  besides  ammonia,  volatile  acids,  leucin  and  tyrosin, 
aromatic  oxyacids,  and  a  mixture  of  bases.  Indol,  skatol, 
phenol,  and  cresol  were  not  found.  The  ferments  produced 
by  these  bacteria  resemble  very  closely  in  their  action  lab  and 
trypsin,  except  that  the  latter  is  not  known  to  produce  aro- 
matic oxyacids. 

Besides  these  main  classes  of  bacteria,  there  are  certain  varie- 
ties which  cause  changes  in  milk  the  exact  clinical  significance 
of  which  is  not  thoroughly  understood.     Their  presence  ren- 


208  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

ders  the  use  of  such  milk  undesirable  if  not  unsafe;  fortu- 
nately, their  presence  can  readily  be  detected. 

The  bacillus  cyanogenes  or  syncyanus,  which  is  only  active  in 
acid  milk,  and  the  bacillus  cyaneo-fluorescens  of  Zangemeister 
cause  a  blue  color  in  milk.  A  red  color  is  due  to  the  presence 
of  the  micrococcus  prodigiosus,  the  sarcina  rosea,  the  bacillus 
lactis  erythrogenes,  and  the  saccharomyces  rubra.  A  yellow 
color  is  due  to  the  bacillus  synxanthus.  Mossier  and  Zundel 
have  proved  that  the  ingestion  of  such  colored  milk  can  set 
up  a  gastro-enteritis  (Marfan). 

Certain  micro-organisms  have  the  property  of  rendering  milk 
viscous.  These  are  the  micrococcus  of  Schmidt-Miihlheim,  the 
actinobacter  (Duclaux),  the  bacillus  lactis  pituitosi  (Loffier), 
the  bacillus  lactis  viscosus  (Adametz),  the  streptococcus  Hol- 
landicus  (Weigmann),  the  micrococcus  of  Freudenreich,  the 
bacterium  of  Guillebeau,  the  bacterium  Hessii,  etc. 

Certain  yeasts  are  also  found,  especially  in  milk  which  has 
undergone  coagulation.  Among  these  are  the  saccharomyces 
lactis,  the  saccharomyces  rubra,  and  the  penicillium  glaucum.105 

Marfan.105  Of  the  various  organisms  described,  the  groups 
of  lactic  acid  and  peptonizing  bacteria  are  most  to  be  feared. 
They  may  do  harm  in  one  of  two  ways :  either  by  their  pres- 
ence in  excessive  numbers  (this  is  more  apt  to  occur  during 
the  summer  months  when  conditions  are  favorable  for  their 
rapid  multiplication)  or  through  the  products  of  their  activity, 
such  as  butyric,  lactic,  propionic,  and  valeric  acids,  or  leucin, 
tyrosin,  ammoniacal  compounds,  and  fatty  acids.  Among  other 
toxic  products  which  result  from  bacterial  activity  especial 
attention  should  be  called  to  tyrotoxicon,  isolated  by  Victor 
Vaughan,  of  Ann  Arbor,  from  putrefied  cream  and  cheese,  and 
spasmotoxine,  found  by  Brieger  in  putrefied  milk. 

The  Transmission  of  Infectious  Diseases  by  Milk. 
Wyssokowitsch  established  the  law  that  healthy  glandular 
epithelium  does  not  permit  of  the  passage  of  microbes.    Basch 


BACTERIOLOGY.  209 

and  Weleminsky,195  in  experimenting  with  pathogenic  germs, 
have  found  that  only  those  bacteria  pass  into  the  milk  which 
give  rise  to  hemorrhage  or  local  disease  of  the  mammary  gland ; 
in  other  words,  bacteria  are  not  excreted  by  the  mammary 
gland,  but  enter  the  milk  only  when  the  natural  barriers  are 
broken  down  by  hemorrhagic  or  other  necroses. 

Tuberculosis. 

It  is  certain  that  the  milk  of  phthisical  animals  can  cause 
tuberculosis  in  laboratory  animals  fed  on  it  or  inoculated  with 
it  under  the  skin  or  in  the  peritoneum.  Tubercular  disease 
of  the  udder  or  teat  of  the  cow  will  almost  certainly  give 
rise  to  tubercular  infection  of  the  milk;  when  the  disease  is 
confined  to  other  parts  of  the  body,  the  milk  of  the  animal 
may  or  may  not  contain  tubercular  virus.  Bollinger,  Nocard, 
and  Galtier  consider  that  the  milk  is  certainly  virulent  only 
when  the  teat  is  affected  by  tuberculosis;  on  the  other  hand, 
Bang,  Csokor,  Ernst,  Hirschberger,  and  Koubassoff  have  found 
the  milk  virulent  even  when  the  disease  was  limited  to  other 
parts  of  the  body.  All  are  agreed  that  the  diagnosis  of  mam- 
mary tuberculosis  in  its  early  stages  is  very  difficult.105 

Clinical  evidence  has  proved  that  milk  from  tubercular  ani- 
mals can,  and  undoubtedly  does,  give  rise  to  tubercular  infec- 
tion through  the  gastro-intestinal  tract;  however,  tuberculosis 
by  ingestion  is  much  less  frequent  than  tuberculosis  by  in- 
halation. 

Holt  believes  that  the  danger  of  transmitting  tubercular 
infection  to  infants  by  cow's  milk  is  greatly  exaggerated. 
Becorded  cases  of  such  infection  are  extremely  rare.  In  a 
series  of  one  hundred  and  nineteen  autopsies  on  tubercular 
patients,  nearly  all  infants,  he  found  no  instance  of  it.  North- 
rup,  in  his  large  experience,  came  across  but  one  undoubted 
case. 

H.  Johnson  Collins  2T  calls  attention  to  the  rarity  of 
tubercular  infection  in  infants  from  raw  milk.     The  inves- 

14 


210  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

tigations  of  Gregari,  Strauss,  arid  Wurtz  show  that,  so  long 
as  the  gastric  juice  retains  a  normal  degree  of  acidity,  tuber- 
culosis of  the  alimentary  canal  is  unlikely  to  occur.  Kurlow 
and  Wagner  consider  the  gastric  juice  to  be  a  strong  bacteri- 
cidal agent. 

At  a  meeting  of  the  Medical  Society  of  the  County  of  New 
York,  January  29,  1900,234  H.  W.  Conn,  of  Wesleyan  Univer- 
sity, stated  that  it  is  still  uncertain  whether  tuberculous  pro- 
cesses in  the  cow  which  were  localized  in  parts  of  the  body 
other  than  the  udder  would  lead  to  the  appearance  of  tubercle 
bacilli  in  the  milk  of  that  animal.  Of  course  this  does  not 
refer  to  general  tuberculosis.  From  the  fact  that  primary 
intestinal  tuberculosis  in  man  is  rare,  and  because  it  is  proba- 
ble that  the  organisms  of  human  and  of  bovine  tuberculosis 
are  not  identical,  Conn  thinks  that  there  is  good  reason  for 
believing  that  the  danger  of  contracting  tuberculosis  from 
drinking  milk  has  been  greatly  exaggerated. 

Koch,261  at  the  recent  meeting  of  the  British  Congress  on 
Tuberculosis,  July  23,  1901,  emphasized  that  human  and  bovine 
tuberculosis  were  distinct  forms  of  infection  and  could  not  be 
transmitted  from  one  species  to  the  other.  He  based  these 
statements  on  animal  experiments  with  human  tubercle  ba- 
cilli and  on  the  rarity  of  primary  intestinal  tuberculosis  in 
man.  In  the  few  positive  cases  in  which  this  had  occurred 
among  thousands  of  autopsies  he  considered  that  it  was  im- 
possible to  exclude  accidental  infection  with  the  widely  propa- 
gated bacilli  of  human  tuberculosis.  He  believes,  therefore, 
that  the  infection  of  human  beings  with  bovine  tuberculosis 
is  of  very  rare  occurrence. 

Whether  the  milk  of  a  tubercular  woman  can  affect  the 
nursing  infant  is  also  a  matter  of  dispute ;  the  conditions  may 
fairly  be  considered  analogous  to  those  in  the  cow.  Eoger  and 
Gamier,  in  the  Semaine  Medicate,  February  23,  1900  (abstract 
in  the  Philadelphia  Medical  Journal,  June  23,  1900),  report 
a  case  in  which  tubercle  bacilli  were  isolated  from  the  milk 


BACTERIOLOGY.  211 

of  a  woman  suffering  from  pharyngeal  and  pulmonary  tuber- 
culosis. The  milk,  when  injected  into  a  guinea-pig,  caused 
death  in  thirty-three  days,  with  typical  generalized  lesions. 

While  the  milk  of  a  tubercular  animal  may  contain  no  tuber- 
cle bacilli,  it  is  possible  that  the  toxins  elaborated  by  them 
may  be  present  and  constitute  a  source  of  danger  to  the  infant 
using  such  milk. 

As  milk  furnishes  a  good  culture  medium  for  most  varieties 
of  bacteria,  its  accidental  infection  with  the  germs  of  any  of 
the  infectious  diseases,  such  as  cholera,  typhoid  fever,  diph- 
theria, etc.,  will  render  such  a  milk  unfit  for  use. 

Diseased  conditions  of  the  cow,  such  as  aphthous  fever,  in- 
fectious mammitis,  anthrax,  etc.,  or,  in  the  woman,  pneumonia, 
typhoid  fever,  scarlet  fever,  etc.,  will  also  constitute  a  contra- 
indication to  the  use  of  their  milk  105  (see  page  169,  Bendix). 

It  seems  hardly  necessary  to  enumerate  all  the  other  micro- 
organisms which  have  been  found  in  milk.  Owing  to  the  lack 
of  uniformity  among  different  observers  in  their  methods  of 
study  and  in  their  descriptions  of  bacteria,  it  seems  probable 
that  numerous  duplicates  of  the  same  species  have  been  de- 
scribed as  distinct  entities  (Conn).  For  the  purposes  of  infant 
feeding  it  is  not  necessary  to  consider  more  than  the  three 
main  groups, — namely,  the  lactic  acid  group,  the  proteolytic 
or  peptonizing  group,  and  what  may  be  called  the  pathogenic 
group.  According  to  Escherich,  the  bacillus  coli  communis 
can  be  included  among  the  first,  since  it  possesses  the  power 
of  splitting  up  lactose  into  lactic  acid. 

The  role  played  by  bacteria  in  the  gastro-intestinal  tract 
remains  to  be  briefly  discussed.  Investigations  to  determine 
the  relation  which  bacterial  activity  bears  to  the  digestive  pro- 
cesses give  us,  at  best,  unsatisfactory  results,  since  it  is  mani- 
festly impossible  to  reproduce  the  conditions  which  obtain  in 
the  intestines  of  the  living  organism. 

Biedert  7  considers  that  intestinal  putrefaction  is  held  in 
check  principally  by: 


212  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

I.  Free  hydrochloric  acid,  which  is  at  its  maximum  in 
breast-fed  children  in  the  intervals  between  feedings  (Langer- 
mann) . 

II.  Lactic  acid,  which  prevents  the  other  forms  of  fermenta- 
tion in  the  stomach  and  small  intestines  (Biedert,  Escherich, 
Richet). 

III.  Fat  and  fatty  acids  in  the  large  intestines. 

IV.  The  absorption  at  the  right  time  of  the  water  and  al- 
buminoid constituents  of  the  food,  thus  leaving  the  lower 
intestine  poor  in  these  materials,  and  preventing  the  excessive 
growth  of  bacteria  until  the  whole  is  excreted  with  the  faeces. 
Gilbert  and  Dominichi  came  to  the  same  conclusions  (Dis- 
cussions of  the  Biological  Society,  Paris,  1894).  They  found 
fewest  microbes  in  the  duodenum ;  from  that  point  their  num- 
ber increased  until  it  was  greatest  at  the  ileo-caecal  valve,  to 
decrease  towards  the  rectum  and  anus. 

Escherich  (Deutsch.  Med.  Woch.,  October  6,  1898)  empha- 
sizes the  antiseptic  action  of  lactic  acid  fermentation,  and  draws 
attention  to  the  fact  that  the  gastric  juice  of  infants  fed  on 
cow's  milk  is  a  poor  disinfectant,  since  so  little  free  hydro- 
chloric acid  is  present. 

Biedert7  finds  that  the  bacteria  chiefly  concerned  in  fer- 
mentative processes  are : 

I.  The  bacillus  lactis  aerogenes,  which  predominates  in  the 
upper  part  of  the  small  intestine.  It  splits  up  lactose  into 
lactic  acid,  carbon  dioxide,  and  water,  and  thus  ferments  the 
chyme.  By  the  production  of  acid  it  maintains  an  acid  medium 
or  reaction. 

II.  The  bacillus  coli  communis,  which  predominates  in  the 
lower  intestine.  It  may  flourish  in  either  acid  or  alkaline 
media,  and  is  capable  of  forming  acid  out  of  lactose.  It  is  able 
to  split  up  neutral  fats  into  fatty  acids,  which  it  does  chiefly 
in  the  large  intestine. 

The  latter  is  the  predominating  germ  of  the  faeces.  Other 
forms  are  also  found,  such  as  the  hay  bacillus,  the  tetracoccus, 


BACTERIOLOGY.  213 

the  white  and  red  hay  bacillus,  the  capsulated  hay  bacillus, 
numerous  cocci,  etc. 

Escherich.48  The  bacillus  lactis  aerogenes  owes  its  predomi- 
nance in  the  small  intestine  to  the  lactic  acid  which  it  produces, 
in  connection  with  its  power  to  live  on  the  products  of  the 
decomposition  of  sugar  in  the  absence  of  oxygen.  Not  until 
the  sugar  is  exhausted  in  the  colon  is  the  field  free  for  other 
bacteria.  First,  the  bacillus  coli  communis,  which  lives  on  rem- 
nants of  sugar  and  albumin  and  busies  itself  in  splitting  up 
fats.  It  is  also  an  agent  of  putrefaction,  acting  on  the  casein 
residues,  which  are  often  considerable  in  artificially  fed  chil- 
dren. Where  the  bacillus  lactis  aerogenes  gives  way  to  the 
bacillus  coli  communis  at  the  end  of  the  ileum,  we  find  that 
the  intense  acid  reaction  becomes  weaker  and  yields  to  an 
alkaline  reaction,  due  to  the  greater  activity  of  the  intestinal 
and  pancreatic  secretions.  At  this  point  the  protection  which 
lactic  acid  had  given  to  the  casein  ceases  (SchlichterX.  The 
acid  reaction,  especially  in  the  case  of  breast-fed  children, 
persists  until  near  the  end  of  the  small  intestine  (Biedert, 
Heubner). 

The  breast-fed  child  leaves  only  a  small  casein  remnant,  but 
a  relatively  greater  sugar  and  lactic  acid  remnant.  Out  of 
the  (comparatively)  large  fat  remnant  the  bacillus  coli  com- 
munis forms  fatty  acids  in  considerable  quantity,  thus  pro- 
longing the  acid  reaction.  When  the  infant  is  artificially  fed, 
casein  with  its  lime  salts  and  its  other  alkaline  products  is 
apt  to  be  conspicuous  in  the  food  residue.  Its  presence  checks 
acid  fermentation. 

Bacteria  undoubtedly  serve  the  purpose  of  helping  to  dis- 
integrate food-stuffs,  especially  those  of  tenacious  vegetable 
fibre  (von  Hoffmeister  in  Neumeister's  "  Text-Book  of  Physio- 
logical Chemistry,"  vol.  i.,  1893-1895).  This  action  may  be 
a  harmless  one  or  may  result  in  the  formation  of  noxious 
products.  When  the  infant  is  healthy,  the  intestine  is  emptied 
before  any  marked  production  of  toxins  occurs. 


214  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

Schlossmann  136  has  conducted  a  series  of  experiments  on 
the  starch-decomposing  properties  of  certain  bacteria.  He 
used  pure  cultures  of  the  bacillus  lactis  aerogenes  and  the 
bacillus  coli  communis,  and  found  that  relatively  high  per- 
centages of  starch  were  decomposed  without  the  production  of 
sugar.  He  concludes,  therefore,  that  it  is  probable  that  a 
greater  or  less  proportion  of  the  starch  in  an  infant's  diet 
cannot  be  utilized  for  the  needs  of  the  organism.  Since  the  con- 
ditions of  the  experiment  can  hardly  be  said  to  reproduce  those 
which  obtain  in  the  gastro-intestinal  tract  of  the  infant,  it  would 
seem  that  his  conclusions  cannot  possess  much  clinical  value. 

Biedert  draws  attention  to  the  fact  that  the  addition  of 
starch  and  lactose  to  the  infant's  diet  favors  the  production 
of  an  acid  reaction.  Baginsky  and  Moro  have  also  found  that 
the  bacillus  coli  communis  and  the  bacillus  lactis  aerogenes 
can  decompose  starch  without  the  production  of  sugar. 

Escherich  has  proved  that  different  forms  of  bacteria  can 
split  up  sugar.  As  gas  is  produced,  which  passes  off  with  the 
faeces,  he  thinks  that  a  portion  of  the  sugar  would  thereby 
be  lost  for  the  needs  of  the  organism. 

Hammarsten  calls  attention  to  the  fact  that,  besides  the 
action  of  enzymes  in  the  intestinal  tract,  we  have  to  take  into 
consideration  fermentative  and  putrefactive  changes  due  to 
the  action  of  bacteria.  These  are  less  intense  in  the  upper 
bowel,  increase  as  we  descend  to  the  ileo-caacal  valve,  and  then 
diminish  in  the  large  intestine,  sigmoid  flexure,  and  rectum. 

So  long  as  the  intestinal  reaction  is  strongly  acid,  fermen- 
tation occurs,  but  not  putrefaction.  Gamgee  asserts  that  the 
amount  of  acid  formed  by  the  organized  ferments  is  so  great 
that  the  intestinal  content,  from  the  pylorus  to  the  cascum,  is 
always  acid  in  reaction. 

Intoxications  through  Milk. 
Sonnenberger  205  lays  stress  on  the  possibility  of  intoxica- 
tion by  plant  alkaloids  which  have  gained  entrance  into  the 


BACTERIOLOGY.  215 

milk  from  the  fodder.  Biedert,  Meinert,  Gaertner,  Alt,  and 
Scholl  have  also  testified  their  belief  that  enteric  diseases  in 
the  infant  can  have  their  origin  in  intoxications  from  this 
source.  Scholl  emphasizes  the  importance  of  careful  inspection 
of  the  fodder,  since  the  alkaloids  and  toxins  contained  in  the 
milk  of  cattle  fed  on  these  poisonous  weeds  cannot  be  purified 
with  certainty  by  the  Soxhlet  process. 

We  know  that  the  mammary  gland,  besides  its  other  proper- 
ties, possesses  that  of  eliminating  poisons;  this  has  recently 
been  demonstrated  conclusively  by  Frohner  (Monatsheft  fur 
Praht.  Heilkunde,  Bd.  ii.).  Schneidemiihl,  in  his  "Text- 
Book  of  Comparative  Pathology,"  vol.  ii.,  1896,  makes  this 
statement  regarding  the  excretion  of  poisons  by  the  mammary 
gland :  "  Milch-cows  have  a  greater  power  of  resistance  against 
poisonous  substances  than  other  animals,  because  the  height- 
ened activity  of  the  mammary  gland  brings  about  a  more  rapid 
and  complete  elimination  of  the  poison  (which  has  found  en- 
trance) than  in  other  animals." 

The  source  of  these  poisons  is  to  be  found  in  the  plant  alka- 
loids; even  in  minute  amounts  their  ingestion  in  milk  may 
give  rise  to  serious  symptoms,  although  the  cattle  which  have 
fed  on  the  plants  containing  them  show  no  symptoms  of  poi- 
soning. The  poisonous  weeds  are  most  often  found  in  clover 
fields;  among  them  are  colchicum,  digitalin,  hyoscyamus, 
papaver  somniferum,  conium  maculatum,  hellebore,  euphorbia, 
sinapis,  etc. 


CHAPTER   IX. 
STERILIZATION    AND    PASTEURIZATION. 

Most  authorities  are  agreed  as  to  the  advisability  of  the  use 
of  heat  in  preparing  milk  for  an  infant's  meal,  differing  only 
in  their  choice  of  the  degree  to  be  employed.  On  the  other 
hand,  it  is  well  recognized  that  the  ideal  to  be  always  sought 
for  is  milk  obtained  and  handled  with  such  strict  precautions 
as  to  be  nearly  sterile  and  kept  free  from  contamination  until 
administered.  Such  a  milk  does  not  require  any  process  of 
heating  for  the  destruction  of  germs,  but  unfortunately  its 
production  is  limited  in  amount  and  necessitates  such  expense 
as  to  place  it  beyond  the  reach  of  all  but  a  favored  few.  In 
preparing  food  for  the  majority  of  infants,  at  least  during  the 
summer  months,  we  will  have  to  employ  some  degree  of  heat. 

Jacobi  76  says  that  "  as  long  as  cows  are  tubercular,  and 
milk  is  exposed  to  contagion  from  scarlet  fever,  diphtheria, 
typhoid  fever,  etc.,  as  ordinarily  obtained  it  needs  to  be  boiled." 
H.  J.  Campbell,29  however,  calls  attention  to  the  fact  that 
foul  milk  cannot  be  rendered  safe  by  any  amount  of  boiling 
or  by  other  methods,  apropos  of  which  is  the  report  by  Mar- 
fan 105  of  an  epidemic  of  severe  gastro-enteritis  in  children 
fed  on  sterilized  cow's  milk.  The  milk  was  sixteen  hours  old 
when  sterilized,  allowing  sufficient  time  for  the  development 
of  toxic  substances  which  are  not  affected  by  sterilization. 

Jemma,236  in  the  Rev.  Mens,  des  Mai.  de  VEnfance,  vol. 
xviii.,  No.  II.,  reports  the  results  of  his  studies  on  the  milk 
of  tubercular  animals.  He  found  that  young  rabbits  fed  on 
sterilized  milk  containing  dead  tubercle  bacilli  died  within 
from  fifteen  to  twenty  days  of  advanced  cachexia  or  later  of 
marasmus.  Other  cases  fed  on  plain  sterilized  milk  or  on 
their  mother's  milk  flourished.  The  autopsies  showed  only 
216 


STERILIZATION   AND   PASTEURIZATION.  217 

enteritis  and  fatty  degeneration  of  the  liver.  It  is  therefore 
erroneous  to  believe  that  boiling  or  sterilization  obviates  the 
dangers  of  using  milk  from  tubercular  animals. 

Failures  in  infant  feeding  will  continue  to  occur,  even  when 
the  milk  administered  is  absolutely  sterile,  for,  as  Welling- 
ton Stewart  126  has  pointed  out,  such  a  milk  becomes  alive 
with  micro-organisms  a  few  minutes  after  its  ingestion.  No 
one  will  deny,  however,  that  the  healthy  infant  can  more  suc- 
cessfully digest  a  pure  milk  than  one  contaminated  with  germs, 
many  of  which  may  be  entirely  foreign  and  harmful  to  a 
marked  degree. 

Methods  of  heating  Milk. 
Three  methods  are  recommended, — namely,  pasteurization, 
sterilization,  and  boiling.  Great  confusion  exists  in  the  use 
of  the  term  "  sterilization."  As  will  be  seen,  complete  sterili- 
zation cannot  be  obtained  at  100°  C.  in  less  than  from  one 
and  a  half  to  two  hours.  Unless  the  method  employed  is  accu- 
rately described,  however,  it  is  impossible  to  decide  whether 
such  a  complete  process  or  its  equivalent  has  been  carried  out. 
As  a  general  rule,  the  term  seems  to  be  applied  to  any  process 
which  carries  the  temperature  to  or  above  100°  C.  for  a  certain 
time  in  some  sort  of  an  apparatus.  This  may  or  may  not 
secure  the  absolute  destruction  of  all  germs,  but  for  purposes 
of  discussion  the  terms  pasteurization,  sterilization,  and  boil- 
ing may  be  accepted  as  defined  below. 

Pasteurization. 

This  method  has  taken  its  name  from  part  of  a  process 
which  Pasteur  recommended  very  successfully  for  the  preserva- 
tion of  wine  and  beer. 

To  R.  G.  Freeman,  of  New  York,  the  credit  belongs  of 
having  drawn  the  attention  of  the  profession  in  this  country 
to  pasteurization,  and  of  devising  an  apparatus  for  the  prepa- 
ration of  milk  in  this  way.    He  recommends  that  milk  should 


218  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

be  heated  to  a  temperature  of  68°  C.  (155°  F.)  for  thirty 
minutes.  This  destroys  most  of  the  bacteria,  including  those 
of  tuberculosis,  typhoid  fever,  and  diphtheria,  and  causes 
practically  no  chemical  change  in  the  milk,  not  even  altering 
its  taste. 

Holt  defines  pasteurization  as  that  method  by  which  the 
temperature  is  raised  to,  and  maintained  at,  75°  C.  (167°  F.) 
for  twenty  minutes.  This  destroys  the  bacilli  of  cholera, 
typhoid,  diphtheria,  and  tuberculosis,  the  bacillus  coli  com- 
munis, and  ordinary  pathogenic  germs.  It  does  not  destroy 
spores,  and  milk  so  prepared  will  keep  for  two  or  three  days 
at  room  temperature.  It  does  not  alter  the  taste;  moreover, 
the  character  and  digestibility  of  the  curd  are  not  affected. 
Whether  there  are  any  changes  in  the  nutritive  value  of  the 
milk  is  a  point  not  yet  settled.  Holt  believes  that  pasteuriza- 
tion is  sufficient  for  ordinary  purposes,  but  that  in  cities  during 
very  hot  weather,  when  ice  is  scarce  and  milk  highly  con- 
taminated, sterilization  is  imperative. 

Cautley  38  considers  that  pasteurization  at  from  70°  to 
75°  C.  (158°  to  167°  F.)  for  thirty  minutes,  followed  by  rapid 
cooling  in  clean,  well-stoppered  bottles,  is  sufficient  for  all 
practical  purposes.  Such  a  milk  should  not  be  kept  longer 
than  from  twelve  to  twenty-four  hours.  It  is  not  seriously 
changed  either  chemically  or  in  its  taste;  therefore  he  recom- 
mends it  as  a  general  rule. 

Freeman.55'  56> 157  Pasteurized  milk  was  distributed  during 
a  period  of  three  years  to  the  poor  of  New  York  City  in  the 
summer  months.  Eoutine  dilutions  were  used:  in  some,  milk 
and  water  in  equal  parts  plus  lactose  and  lime-water ;  in  others, 
milk  and  barley-water  equal  parts  plus  cane-sugar.  During 
the  three  years  of  its  use  the  number  of  deaths  from  diarrhceal 
diseases  was  less  by  eight  hundred  and  sixty  than  in  the  three 
preceding  years.  Over  one  million  bottles  were  given  out 
during  this  time. 

F.  Siegert,  of  Strasburg,  calls  attention  to  the  fact  that, 


STERILIZATION   AND   PASTEURIZATION.  219 

since  the  year  1893,  Forster,  of  Amsterdam,  had  employed 
pasteurization  at  65°  C.  (150°  F.)  for  fifteen  minutes,  and  had 
found  the  results  satisfactory  in  freeing  the  milk  from  patho- 
genic germs.  Siegert  carried  out  the  same  method  in  Stras- 
burg  on  a  large  scale  with  good  results. 

Leeds  93  draws  attention  to  the  practical  sufficiency  of  pas- 
teurization as  regards  the  destruction  of  pathogenic  germs, 
and  is  in  favor  of  carrying  out  the  process  immediately  after 
milking.  The  advantages  claimed  for  this  method  are  that 
the  temperature  of  the  milk  need  be  raised  only  from  98.4°  F. 
(blood-heat)  to  157°  F.  (instead  of  from  40°  to  50°  F.,  the 
usual  temperature  at  which  milk  is  kept).  This  saves  expense 
and  prevents  the  development  of  bacteria  and  the  production 
of  toxins. 

Monti  advises  to  heat  milk  to  60°  C.  (140°  F.)  for  ten 
minutes,  then  to  cool  to  6°  or  8°  C.  (42.8°  or  46.4°  F.).  The 
milk  should  be  kept  at  this  temperature  until  used.  This 
process  kills  most  of  the  germs  and  prevents  sporulation  with- 
out alteration  of  the  milk  constituents. 

Kavenel  260  gives  Sternberg's  table  of  the  thermal  death- 
point  of  some  of  the  most  important  bacteria. 

Bacillus  diphtheria? 58°  C.  (136°  F. )  for  ten  minutes 

Typhoid  bacillus 56°  C.  (133°  F.)  for  ten  minutes 

Pneumococcus 52°  C.  (125°  F. )  for  ten  minutes 

Bacillus  coli  communis  .  60°  C.  (140°  F.)  for  ten  minutes 

Bacillus  acidi  lactici 56°  C.  (133°  F.)  for  ten  minutes 

Staphylococcus  pyogenes 

aureus 58°  C.  (136°  F. )  for  ten  minutes 

Staphylococcus  pyogenes 

albus 62°  C.  (144°  F. )  for  ten  minutes 

Bang,  of  Copenhagen,259  found  that  a  temperature  of  60°  C. 
(140°  F.)  for  fifteen  minutes  was  sufficient  to  destroy  all  the 
tubercle  bacilli  in  milk,  so  as  to  prevent  infection  when  they 


220  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

were  injected  into  the  peritoneal  cavity;  this  degree  of  heat 
was  sufficient  to  weaken  the  bacilli  so  that  after  pasteurization 
for  two  minutes  they  were  incapable  of  infecting  through  the 
alimentary  canal.  In  another  series  of  experiments  higher 
temperatures— 70°  C.  (158°  P.),  75°  C.  (167°  F.),  and  80°  C. 
(176°  F.) — were  applied  to  milk  from  tuberculous  udders, 
but  sometimes  failed  to  destroy  the  tubercle  bacilli.  Since  the 
milk  was  heated  in  open  bottles,  the  failure  to  destroy  the 
germs  was  ascribed  to  the  uneven  application  of  the  heat  to 
the  pellicle  and  to  the  foam  on  the  surface  of  the  milk. 

Theobald  Smith  255  had  previously  discovered  from  ex- 
periments with  pure  cultures  of  tubercle  bacilli  in  different 
media  that  a  temperature  of  60°  C.  (140°  F.)  for  fifteen  min- 
utes was  sufficient  to  destroy  all  the  bacilli,  and  that  most  of 
the  germs  were  destroyed  within  from  five  to  ten  minutes. 
He  did  not  obtain  equally  good  results  with  tubercle  bacilli 
in  milk,  and  considered  that  this  was  due  to  the  protection 
of  the  pellicle.  H.  L.  Eussell,  of  Wisconsin  University,  obtained 
similar  results.  He  found  that  heating  to  60°  C.  in  closed 
bottles  destroyed  the  tubercle  bacilli  in  ten  minutes. 

Forster  260  gives  the  thermal  death-point  of  the  tubercle 
bacillus  as  follows:  65°  C.  (150°  F.)  for  thirty  minutes, 
68°  C.  (155°  F.)  for  fifteen  minutes,  75°  C.  (167°  F.)  for 
ten  minutes. 

Blackader.207  Wroblewsky  has  called  attention  to  the  fact 
that  certain  of  the  calcium  salts  which  are  normally  soluble 
are  made  to  enter  into  insoluble  combinations  by  high  tem- 
peratures, while  Duclaux  has  pointed  out  that  the  gastric 
ferments  are  effective  only  in  the  presence  of  minute  quantities 
of  calcium  and  other  mineral  salts,  the  mineral  varying  with 
the  specific  form  of  fermentation  (see  Conradi).  If  the  cal- 
cium salts  are  rendered  insoluble  by  heat,  then  the  coagulation 
of  casein  will  to  that  extent  be  arrested  or  delayed.  In  cor- 
roboration of  this  view  we  know  that  boiled  milk  undergoes 
coagulation  by  rennet  only  with  much  difficulty.     Since  this 


STERILIZATION   AND   PASTEURIZATION.  221 

primary  coagulation  in  the  stomach  appears  to  be  necessary 
for  the  normal  digestion  of  milk  and  its  absorption  into  the 
system,  it  is  certainly  questionable  whether,  as  a  rule,  boiled 
milk  can  be  absorbed  and  assimilated  as  readily  as  milk  which 
has  not  been  brought  to  a  temperature  sufficient  to  change  the 
condition  of  its  calcium  salts.  On  the  other  hand,  this  action 
may  sometimes  be  of  distinct  advantage  in  those  conditions 
of  the  infant's  stomach  in  which  the  action  of  rennet,  either 
directly  or  reinforced  by  the  presence  of  fermenting  bacteria, 
is  so  intense  as  to  lead  to  the  development  of  firm  curds. 

Blackader  thinks  that  unheated  milk  probably  contains  fer- 
ment-like bodies  which,  when  absorbed,  are  of  distinct  value 
to  the  organism.  Babcock  and  Eussell  (Fourteenth  Annual 
Keport  of  the  Wisconsin  Experiment  Station)  discovered  that 
milk  obtained  in  a  condition  of  perfect  sterility  undergoes  self- 
digestion  owing  to  the  presence  of  a  trypsin  which  is  readily 
destroyed  by  heat.  Blackader  prefers  to  use  always  good  un- 
heated milk.  When  this  cannot  be  obtained,  he  employs  a  tem- 
perature of  60°  C.  (140°  F.)  for  fifteen  minutes. 

Conradi  240  found  that  the  subjection  of  milk  to  tempera- 
tures of  over  80°  C.  (176°  F.)  lowered  the  coagulation  point 
of  the  milk  in  the  presence  of  lime  and  similar  salts  from  8° 
to  12°  C. ;  on  the  other  hand,  postponing  the  process  of  lab- 
coagulation.  These  facts  prove  that  temperatures  of  over 
80°  C.  cause  a  lasting  chemical  and  physical  alteration  in  the 
milk. 

Troitsky  141» 142  considers  it  established  that  ordinary  lactic 
acid  ferments  and  pathogenic  bacteria  encountered  in  milk,  in- 
cluding tubercle  bacilli,  are  destroyed  by  a  temperature  of  80° 
C.  (176°  F.)  for  ten  minutes  or  68°  C.  (155°  F.)  for  thirty 
minutes.  The  casein  ferments  resist  heat  much  better.  The 
bacillus  subtilis,  tyrothrix  tenuis,  and  bacillus  mesentericus 
vulgatus  produce  spores  which  are  only  destroyed  at  very  high 
temperatures.  If  the  adult  germ  succumbs  at  about  100°  C, 
its  spores  can  resist  a  temperature  of  115°  C.  for  one  minute. 


222  THE  ARTIFICIAL   FEEDING   OF   INFANTS. 

Jacobi  19  thinks  that  for  the  purpose  of  pasteurization  "  milk 
should  be  subjected  to  a  temperature  of  from  65°  to  68°  C. 
(150°  to  155°  F.)  for  twenty  minutes,  but  that  it  may  be  wise 
to  extend  the  process  over  a  longer  time." 

Johannessen  208'  23°  thinks  that  with  proper  precautions  as 
to  the  feeding  of  cows,  etc.,  we  may  hope  to  obtain  milk  which 
is  primarily  free  from  germs.  Under  the  present  conditions 
milk  must  be  pasteurized  and  then  kept  cool  (below  18°  C), 
and  administered  within  twelve  hours.  Heating  to  70°  C. 
for  some  time  destroys  pathogenic  germs  without  altering  to 
any  extent  the  chemical  composition  of  the  milk. 

Von  Starck  148»  15°  believes  in  the  efficacy  of  pasteurization 
to  destroy  pathogenic  germs. 

Getty68  had  milk  pasteurized  at  75°  C.  (167°  F.)  for 
twenty  minutes  put  in  separate  sterile  bottles  plugged  with 
sterile  cotton,  cooled  immediately  and  kept  on  ice.  This  was 
distributed  during  June,  July,  August,  and  September  to  a 
large  number  of  children  at  Yonkers,  New  York.  He  asserts 
that  a  reduction  of  seventeen  per  cent,  in  the  total  mortality 
was  effected  during  the  two  years  of  its  use,  and  that  the  num- 
ber of  deaths  from  digestive  disturbances  was  reduced  almost 
one-half. 

Huppe  133  believes  that  milk  is  best  treated  from  a  physio- 
logical stand-point  by  the  application  of  heat  under  75°  C, 
since  greater  temperatures  produce  chemical  changes. 

H.  Johnstone  Campbell  29  thinks  that  pasteurization  pre- 
sents fewer  disadvantages  than  sterilization ;  hence  it  is  gener- 
ally to  be  preferred. 

J.  Lewis  Smith  129  thinks  that  pasteurization  should  always 
be  recommended  and  never  a  higher  temperature. 

Campbell  219  suggests  a  cheap  method  for  home  pasteuriza- 
tion. The  necessary  articles  are  (a)  a  jar,  the  cork  of  which 
is  perforated  for  (b)  a  chemical  thermometer,  and  (c)  sterile 
non-absorbent  cotton.  The  jar  is  filled  with  the  milk  to  be 
pasteurized,  the  cork,  with  the  thermometer  in  place,  inserted, 


STERILIZATION   AND   PASTEURIZATION.  223 

and  the  whole  placed  in  a  saucepan  of  water  and  heated  until 
the  temperature  of  the  milk  reaches  160°  F.  The  sauce- 
pan is  then  set  at  the  back  of  the  stove  for  twenty  minutes. 
The  cork  is  next  replaced  by  a  cotton  plug,  and  the  milk  is 
ready  for  use  or  to  be  cooled  and  kept  until  wanted.  The 
whole  outfit  can  be  obtained  at  the  cost  of  about  one  dollar. 

Carstairs  Douglass,  in  the  Glasgow  Medical  Journal,220 
suggests  that  the  unpleasant  taste  of  boiled  milk  is  in  large 
part  due  to  the  film  which  forms  on  the  sides  of  the  vessel 
above  the  bubbling  fluid.  As  the  fluid  subsides,  this  film 
becomes  overheated  and  charred  and  is  carried  back  into  the 
milk  at  its  next  ebullition.  In  proof  of  this  he  has  noted  that 
if  milk  is  boiled  in  a  flask  and  constantly  agitated,  the  altera- 
tion in  taste  is  much  less.  Douglass  firmly  believes  in  some 
vital  property  of  fresh  milk  which  a  temperature  of  100°  C. 
destroys;  hence  he  prefers  pasteurization. 

Objections  to  Pasteurization. 

Marfan  105  objects  that  pasteurization  requires  complicated 
apparatus  and  the  milk  must  be  cooled  rapidly  afterwards.  It 
keeps  good  for  a  short  time  only,  and  one  is  never  sure  that 
all  the  lactic  ferments  have  been  destroyed;  therefore  he  does 
not  recommend  it. 

Comby  62  considers  that  pasteurization  is  useful  to  preserve 
the  milk,  but  that  all  the  pathogenic  germs  are  not  destroyed. 

Biedert  7  asserts  that  the  lactic  acid  bacilli  are  destroyed  by 
pasteurization,  while  the  proteus  and  the  coli  groups  are  not 
affected.  He  recommends  this  method  only  for  institutions 
in  which  the  danger  of  milk  contamination  is  minimized. 

Koplik.80'  81  Pasteurization  destroys  the  pathogenic  germs 
of  most  known  diseases,  but  it  does  not  destroy  the  milk  bac- 
teria which  are  much  more  frequently  the  cause  of  trouble. 
Most  of  these  fall  under  three  groups :  A.  Those  which  form 
lactic  acid.  B.  Those  which  form  butyric  acid.  C.  Pepto- 
nizing bacteria.     Groups  B  and  C  are  not  affected  by  any 


224  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

temperature  at  or  below  100°  C,  although  cold  inhibits  their 
growth.  Heating  to  from  90°  to  92°  C.  destroys  Group  A. 
Since  Groups  B  and  C  are  not  destroyed  by  pasteurization, 
he  considers  milk  so  prepared  an  uncertain  and  at  times  a 
dangerous  food.  He  therefore  advises  sterilization  for  ten 
minutes  at  either  90°  or  100°  C.  He  has  observed  various 
forms  of  "  milk  infection"  in  infants  fed  on  pasteurized  milk. 

Sterilization. 

Marfan.119  Miquel  found  that  all  germs  are  killed  at  the 
end  of  one  hour  by  heating  to  105°  C,  at  the  end  of  half  an 
hour  by  a  temperature  of  107°  or  108°  C,  and  at  the  end 
of  fifteen  minutes  by  a  temperature  of  110°  C.  Troitsky 
states  that  sterilization  is  complete  only  after  exposure  to 
100°  C.  for  from  one  and  a  half  to  two  hours,  or  even  longer. 
Complete  sterilization  of  milk,  therefore,  can  only  be  accom- 
plished by  heating  it  to  100°  C.  for  from  one  and  a  half  to 
two  hours,  to  105°  C.  for  one  hour,  to  107°  or  108°  C.  for 
half  an  hour,  or  to  110°  C.  for  fifteen  minutes.  (Higher  de- 
grees of  temperature,  daily  sterilization  at  100°  C.  for  thirty 
minutes  during  three  days,  so-called  fractional  sterilization 
or  Tyndallization,  or  heating  in  a  special  apparatus  (auto- 
clave) where  the  pressure  can  also  be  raised,  would  all  serve 
the  same  purpose,  but  practically  these  methods  are  not  in 
use. — Editors.  ) 

To  Soxhlet,  as  Jacobi  well  says,  belongs  the  immortal  merit 
of  having  systematized  and  popularized  the  method  of  boiling 
and  thereby  sterilizing  milk  in  single  portions  for  the  use  of 
infants.  Marfan  believes  that  milk  heated  in  a  double  boiler, 
such  as  the  Soxhlet  apparatus,  to  100°  C.  for  forty  minutes 
will  remain  sterile  from  four  to  five  days  if  the  conditions 
are  favorable.  If  this  is  used  within  twenty-four  hours,  it 
may  be  considered  practically  sterile.  The  same  physical  and 
chemical  changes  are  found  in  this  milk  which  are  found  in 
any  milk  heated  to  or  above  80°  C.    If  rubber  corks  are  used, 


STERILIZATION   AND   PASTEURIZATION.  225 

as  in  the  Soxhlet  apparatus,  a  disagreeable  odor  and  taste  may 
be  imparted  to  the  milk.  Marfan's  experiments  show  that  the 
actual  temperature  of  the  milk  never  exceeds  from  95°  to 
96°  C.,*  so  that  the  casein  ferments  cannot  be  destroyed. 
(The  slow  development  of  the  latter  may  be  explained  by  the 
hermetic  closure  of  the  jars,  which  excludes  all  oxygen. — 
Editors.) 

It  is  probable  that  the  effect  of  a  high  temperature  which 
alters  the  mode  of  coagulation  of  (sterilized)  milk  is  favor- 
able rather  than  unfavorable  to  its  digestion.  The  only  satis- 
factory test  would  be  to  feed  a  series  of  infants  of  like  age  and 
weight  on  sterilized  milk  and  raw  milk,  the  amounts  of  food 
being  carefully  estimated ;  in  other  words,  to  carry  out  metab- 
olism experiments.  The  results  of  test-tube  experiments  are 
too  unlike  the  actual  conditions  to  be  satisfactory.  Marfan's 
practical  experience  leads  him  to  the  following  conclusions: 
with  good  methods  of  purification  by  heat,  accidents  of  feeding 
are  much  reduced  in  number,  gain  in  weight  is  much  more 
steady,  and  gastro-enteritis,  especially  in  its  severe  forms, 
becomes  less  frequent. 

Budin,  in  1892,  found  that  pure  cow's  milk,  if  sterilized, 
could  be  digested  by  the  new-born  infant.  Since  then  this 
view  has  been  corroborated  by  Chavanne,  Variot,  Comby,  B. 
Lazard,  Drapier,  and  Madame  Bres  (1896). 

Marfan  states  that  the  avoidance  of  excessively  high  tem- 
peratures, the  exclusion  of  air,  and  rapid  after-cooling  have 
served  to  diminish  the  changes  brought  about  by  sterilization, 
which  are  found  only  to  a  slight  degree  in  the  ordinary  com- 
mercial sterilized  milk  sold  in  France.  It  is  important  that 
this  milk  should  be  used  within  a  week,  otherwise  the  fat- 
drofnets  will  separate.  Heating  to  40°  C.  and  a  thorough 
shaking  will  restore  the  emulsion.  Estimates  made  by  the 
pharmacist  of  the  Hopital  des  Enfants  Malades  show  that  the 

*  Johannessen 230  says  that  the  temperature  of  the  milk  in  the  bottles  of 
the  Soxhlet  apparatus  rarely  exceeds  96°  C. 

15 


226  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

percentage  of  phosphoric  acid  in  sterilized  milk  is  practically 
always  normal,  provided  the  bottle  is  first  thoroughly  shaken. 
If  the  bottle  is  not  disturbed,  a  layer  of  mucus  is  formed  on 
the  sides  and  bottom,  containing  from  one-half  to  one-thirtieth 
of  the  total  phosphoric  acid  present.  Marfan  does  not  consider 
that  these  facts  constitute  valid  objections  to  the  use  of  steril- 
ized milk. 

Biedert  7  approves  of  sterilization.  The  objection  raised, 
that  lactic  acid  bacteria  are  destroyed  by  this  process,  does 
not  hold,  since  many  of  these  organisms  are  already  present 
in  the  mouth  and  stomach.  The  milk  mixture  should  be  put 
into  separate  bottles,  sterilized,  immediately  cooled,  and  kept 
cool  until  ready  for  use.  Since  the  majority  of  people  are 
unable  to  carry  out  this  process,  simple  boiling  in  a  covered 
receptacle  can  be  recommended,  provided  the  milk  is  not  after- 
wards disturbed. 

Fliigge  has  objected  that  the  fat  separates  in  large  globules 
after  sterilization.  This  can  be  remedied  by  shaking  the  bot- 
tles in  a  circular  direction  before  use. 

Fenwick  52  recommends  sterilization  when  milk  is  liable 
to  be  contaminated;   otherwise  pasteurization  is  preferable. 

Thomson  147  advises  sterilization  for  those  who  live  in  cities, 
as  long  as  dairy  methods  are  so  imperfect.  The  milk  must  be 
sterilized  while  fresh.  Pasteurization  is  not  wholly  satis- 
factory. 

Comby  62  considers  it  indispensable  to  boil  or  sterilize  cow's 
milk  for  young  infants,  especially  in  cities,  owing  to  the  dan- 
gers of  tuberculosis,  aphthous  fever,  etc.  He  permits  the  use 
of  pure  milk  only  in  exceptional  cases,  as  in  the  country  dis- 
tricts or  where  the  cows  react  negatively  to  tuberculin.  Sterili- 
zation prevents  germ  infection  and  causes  molecular  modifica- 
tion of  the  casein  which  renders  it  more  assimilable  for  young 
infants. 

Variot  151  believes  the  best  method  is  to  have  the  milk  ster- 
ilized in  gross  at  115°  C.  at  the  dairy  farms  immediately  after 


STERILIZATION   AND   PASTEURIZATION.  227 

milking.  It  is  then  hermetically  sealed  in  quarter-  and  half- 
litre  bottles.  These  are  distributed  with  careful  directions  as 
to  the  size  of  the  meals.  He  usually  gives  whole  milk  after  one 
month ;  to  those  with  weak  digestion  he  gives  it  after  the  second 
or  third  month.  Before  that  time  milk  should  be  diluted  with 
from  one-third  to  one-fourth  its  amount  of  water.  Most  of 
his  cases  so  treated  (eight  hundred  in  all)  did  well.  Scurvy 
was  never  observed  and  rickets  but  seldom;  many  of  the 
infants,  however,  were  constipated  and  anaemic. 

Baginsky  6  thinks  that  the  Soxhlet  method  gives  the  best 
practical  results,  although  it  does  not  completely  sterilize  the 
milk.  Immediate  cooling  and  use  within  two  days  are  essen- 
tial factors.  Many  children  cannot  digest  milk  so  treated, 
however.    He  has  never  encountered  scurvy  following  its  use. 

Troitsky.141'  142  Sterilization  probably  produces  some 
chemical  changes  in  milk,  but  does  not  render  it  indigestible. 
Under  present  conditions  we  have  no  better  substitute  for 
mother's  milk.  Both  sterilized  and  raw  milk  are  good  culture 
media,  but  germs  grow  less  readily  in  the  former.  The  bottle 
of  sterilized  milk  may  be  opened  once  or  twice  without  be- 
coming infected,  but  each  repetition  increases  the  danger  of 
contamination. 

Koplik.80'  81  Years  of  observation  have  not  borne  out  the 
objection  that  milk  is  rendered  more  difficult  of  digestion  by 
sterilization. 

Starr.133  Sterilized  milk  is  especially  useful  on  a  long 
journey  during  the  heated  term  and  as  a  temporary  change 
of  diet  for  delicate  children  suffering  from  gastro-intestinal 
diseases. 

Ashby  and  Wright  2  think  that  it  is  impossible  to  sterilize 
stale  milk  at  the  home.  If  the  milk  is  fresh  and  clean,  a 
temperature  of  from  70°  to  75°  C.  is  sufficient;  otherwise 
it  should  be  heated  to  100°  C.  for  half  an  hour. 

F.  Gernsheim.67  Variations  in  the  fat  content  of  the  sepa- 
rate bottles  can  be  avoided  only  by  thorough  stirring  and 


228  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

shaking  of  the  milk  just  before  filling.  If  the  milk  is  kept  in 
a  large  vessel,  it  must  be  well  stirred  in  a  circular  direction 
before  pouring.  Contamination  with  germs  is  not  likely  to 
occur  if  the  bottles  have  previously  been  sterilized. 

Objections  to  Sterilization. 

Carstens,  of  Leipsic,  at  the  seventieth  meeting  of  the  So- 
ciety of  German  Naturalists  and  Physicians,  in  1898,  empha- 
sized the  importance  of  cleanliness  in  securing  and  handling 
milk,  and  the  disadvantages  following  the  use  of  sterilized 
milk  (anaemia,  rickets,  and  scurvy).  If  milk  can  be  obtained 
clean  and  fresh,  simple  boiling  for  ten  minutes  is  preferable 
to  sterilization;  otherwise,  we  sterilize  for  thirty  minutes. 
The  administration  of  sterilized  milk  exclusively  beyond  the 
ninth  or  tenth  month  is  not  to  be  recommended.  He  believes 
that  a  dilution  of  one  to  three  is  necessary  only  for  small 
babies  during  the  first  month;  after  the  second  month  we  can 
use  stronger  concentrations. 

Von  Starck,  of  Kiel,150  expresses  these  views :  1.  The  pro- 
longed and  exclusive  use  of  sterilized  milk  for  infants  leads 
in  a  considerable  number  of  cases  to  disturbance  of  nutrition, 
showing  itself  as  severe  anaemia,  rickets,  scurvy,  etc.  2.  The 
uniformity  of  the  diet  is  largely  responsible  for  this,  besides 
the  physical  and  chemical  changes  produced  by  sterilization. 
3.  If  clean  raw  milk  cannot  be  obtained,  the  milk  should  be 
heated,  to  what  degree  and  for  how  long  depends  on  the 
circumstances  of  the  individual  case.  4.  In  certain  condi- 
tions sterilization  is  necessary.  5.  Fresh,  clean  boiled  milk 
is  the  normal  substitute  for  mother's  milk,  and  gives  as  good 
results  as  sterilized  milk  without  the  disadvantages  of  the 
latter. 

Eighty-four  out  of  three  hundred  physicians  in  Schleswig- 
Holstein  reported  the  occurrence  of  rickets,  anaemia,  retarded 
development,  constipation,  etc.,  resulting  from  the  continued 
use  of  sterilized  milk. 


STERILIZATION  AND   PASTEURIZATION.  229 

Dawson  Williams,  Bendix,  Czerny,  and  von  Stark,  of 
Munich,  believe  that  scurvy  may  result  from  the  continued  use 
of  sterilized  milk,  and  in  1895  Starr  reported  five  cases  of 
this  disease  in  infants  under  two  years,  following  its  employ- 
ment. 

Holt  says  that  infants  fed  on  sterilized  milk  are  apt  to  be 
constipated. 

Monti  "  is  convinced  that  the  value  of  milk  as  an  infant 
food  is  distinctly  affected  by  sterilization,  and  that  many  dis- 
advantages are  connected  with  its  use  in  infant  feeding. 
Rickets,  dyspepsia,  and  high-grade  anaemias  are  apt  to  result. 

J.  Kingston  Barton  15  thinks  that  scurvy  will  undoubtedly 
follow  the  use  of  completely  sterilized  milk,  if  no  fresh  food 
is  administered  at  the  same  time. 

H.  Johnstone  Campbell.29  Scurvy  and  rickets  often  fol- 
low the  use  of  sterilized  milk.  Since  it  is  not  well  digested, 
the  infant  receives  an  insufficiency  of  food,  especially  of  the 
fats  and  carbohydrates. 

The  American  Pediatric  Society  has  collected  a  total  of 
three  hundred  and  fifty-six  cases  of  scurvy.3  Out  of  this  num- 
ber, sixty-eight  cases  were  fed  solely  on  sterilized  milk. 

Jacobi  76  calls  attention  to  the  fact  that,  unless  sterilization 
be  complete,  the  resistant  spores  of  bacteria  may  find  a  better 
opportunity  for  development,  since  the  lactic  acid  ferments 
have  been  destroyed.  The  longer  such  milk  is  kept  before  it 
reaches  the  consumer  the  more  dangerous  it  becomes.  Cream 
separates  from  sterilized  milk.  Renk  found  that  this  separa- 
tion occurs  to  a  slight  extent  within  one  week  of  sterilization, 
and  that  later  43.5  per  cent,  of  the  cream  was  separated. 
Jacobi  considers  the  question  of  chemical  changes  not  yet 
definitely  settled.  The  substitution  of  sterilized  milk  for 
mother's  milk  as  the  sole  food  for  the  infant  is  a  mistake. 
Digestive  disturbances  and  rickets  are  frequently  due  to  its 
persistent  use,  and  it  appears  to  be,  at  least  occasionally,  a 
co-operative  cause  of  scurvy. 


230  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

We  have  found  it  convenient  to  place  in  tabulated  form  a 
list  of  the  physical  and  chemical  changes  which  are  said  to 
follow  the  process  of  sterilization. 

A.  Decomposition  of  lecithin  and  nuclein  (Baginsky,  von 
Starck,  Biedert,  Jacobi,  Edlefsen),  also  of  nucleon  (Edlef- 
sen). 

B.  Organic  phosphorus  is  diminished  and  inorganic  phos- 
phorus increased  in  amount  (Baginsky,  1894). 

C.  The  greater  part  of  the  phosphates  are  rendered  insolu- 
ble (Monti,  Dawson  Williams,  H.  Johnstone  Campbell). 

D.  Precipitation  of  the  calcium  and  magnesium  salts  (Ashby 
and  Wright,  Jacobi,  Dawson  Williams,  H.  Johnstone  Camp- 
bell). 

E.  The  greater  part  of  the  carbon  dioxide  is  driven  off 
(Johannessen,  Dawson  Williams,  H.  Johnstone  Campbell). 

F.  Normal  lactic  acid  fermentation  is  prevented  (Biedert). 

G.  Lactose  is  completely  destroyed  (Leeds,  Baginsky).  Du- 
claux  denies  this.  Johannessen  states  that  it  does  not  occur 
below  110°  C. 

H.  "  Caramelization"  of  certain  portions  of  the  lactose 
(Holt,  Eenk,  Monti,  Jacobi,  Carpenter). 

I.  The  fat  emulsion  is  partially  destroyed  or  rendered  im- 
perfect by  the  coalescence  of  the  fat-globules  (Renk,  Biedert, 
Monti,  Ashby  and  Wright,  Jacobi,  J.  Lewis  Smith,  H.  John- 
stone Campbell,  Johannessen). 

J.  Separation  of  the  serum-albumin  begins  at  75°  C.  and 
increases  as  the  temperature  is  raised  (Renk,  Koplik,  Cautley, 
Jacobi,  Freeman,  J.  Lewis  Smith,  H.  Johnstone  Campbell). 

K.  Casein  is  rendered  less  easy  of  coagulation  by  rennet 
(Baginsky,  Leeds,  Holt,  Koplik,  J.  Lewis  Smith,  H.  Johnstone 
Campbell ) . 

L.  Casein  is  slowly  and  imperfectly  acted  upon  by  pepsin 
and  pancreatin  (Leeds,  Holt,  Jacobi,  H.  Johnstone  Campbell). 
Leeds  says  that  the  proteid  substances  become  attached  to  the 


STERILIZATION   AND   PASTEURIZATION.  231 

fat-globules  and  probably  hinder  to  some  extent  fat  assimi- 
lation. 

M.  Peptones  and  toxins  can  be  found  after  prolonged  ster- 
ilization (von  Starck).  They  are  said  to  be  produced  by  the 
action  of  chlorides  on  casein  (A.  Christiaens,  U  Union  Phar- 
maceutique,  August  15,  1894,  cited  by  Marfan). 

H".  The  starch-liquefying  ferment  is  destroyed  and  coagu- 
lated (Leeds,  J.  Lewis  Smith). 

0.  The  taste  is  rendered  objectionable  (Kenk,  Holt,  Caut- 
ley,  H.  Johnstone  Campbell).  Marfan  considers  this  a  small 
objection,  as  the  infant's  taste  is  poorly  developed. 

Boiling. 

Marfan.105  Milk  boils  at  about  101°  C.  It  rises  before 
boiling,  beginning  at  75°  C,  according  to  Comby,  and  85°  C, 
according  to  Gautrelet.  It  is  necessary  to  break  up  the  skim 
on  the  surface  of  the  milk  and  to  keep  it  on  the  fire  until 
large  bubbles  appear.  Milk  boiled  from  three  to  four  minutes 
does  not  contain  lactic  ferments  or  pathogenic  germs,  but  it 
will  not  keep  for  any  length  of  time,  because  the  spores  of  the 
casein  ferments  are  not  destroyed.  The  skim  is  composed  of 
casein,  but,  since  the  latter  is  present  to  excess  in  cow's  milk, 
Marfan  does  not  consider  this  objectionable.  The  increase  in 
density  to  which  Duclaux  and  Crolas  have  called  attention 
is  too  insignificant  to  be  of  any  consequence.  If  milk  can  be 
boiled  directly  after  milking,  and  used  the  same  day,  it  may 
be  employed  without  hesitation. 

Jacobi  76  calls  attention  to  the  fact  that  pasteurization  and 
sterilization  are  logical  developments  of  his  plan  of  boiling 
milk  which  he  advocated  forty  years  ago.  He  asserts  that 
boiling  expels  air.  The  following  bacteria  are  destroyed :  the 
bacilli  of  typhoid  fever,  diphtheria,  tuberculosis,  cholera,  the 
oi'dium  lactis.  Some  varieties  of  proteus  and  most  of  the  bacilli 
coli  communis  are  rendered  innocuous;  the  hay  bacillus  and 
the  bacillus  butyricus  are  not  destroyed.     Jacobi  thinks  that 


232  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

the  daily  home  sterilization  of  milk  is  far  preferable  to  the 
risky  purchase  from  wholesale  dealers  who  cannot  guarantee, 
as  they  cannot  know,  the  condition  of  their  wares. 

Sommerfeld.128  Fliigge  advises  for  practical  work  to  boil 
the  milk  for  a  short  time  (which  destroys  most  of  the  patho- 
genic germs),  then  to  cool  it  rapidly  and  protect  it  from  air 
infection.  Cooling  hinders  or  checks  the  development  of  dan- 
gerous forms,  such  as  the  peptonizing  and  anaerobic  bacteria, 
He  thinks  that  Soxhlet's  method  requires  too  long  boiling  and 
does  not  lay  sufficient  stress  on  rapid  cooling.  Prolonged  heat- 
ing causes  physical  and  chemical  changes  in  milk. 

Czerny  34  advises  boiling  for  ten  minutes. 

Henoch  71  advises  that  only  pure  milk  should  be  used  and 
that  it  should  be  boiled  for  half  an  hour. 

Bendix  10  disapproves  of  boiling  for  more  than  half  an  hour, 
since  change  of  taste  and  other  deleterious  alterations  may  be 
produced.  Milk  so  prepared  should  be  used  within  from 
twenty-four  to  thirty-six  hours  at  the  longest. 

Objections  to  Boiling. 
At  the  Moscow  Congress,  in  1897,  Schlossmann  asserted 
that  boiling  milk  caused  alterations  in  the  fat,  albumins,  and 
phosphorus-containing  substances. 

Chemical  Changes  in  Sterilized  Milk. 

Holt.69  The  changes  in  milk  resulting  from  the  application 
of  heat  begin  at  180°  F.  and  become  more  marked  the  higher 
the  temperature  and  the  longer  it  is  maintained.  Sterilization 
should  be  done  at  the  dairy.  Its  value  consists  in  the  preven- 
tion, not  the  cure,  of  disease;  it  is  unnecessary  if  pure  milk 
can  be  freshly  obtained. 

Eichmond.120  The  most  marked  characteristic  distinguish- 
ing sterilized  from  new  milk  is  the  state  in  which  the  albumin 
exists.  In  milk  which  has  been  heated,  coagulation  does  not  oc- 
cur ;  but  if  it  is  acidified  or  saturated  with  magnesium  sulphate, 


STERILIZATION  AND   PASTEURIZATION.  233 

the  albumin  separates  with  the  casein.  It  appears  to  be  changed 
from  a  soluble  to  a  colloidal  form.  Not  more  than  0.1  per  cent, 
of  albumin  is  found  in  sterilized  milk  in  a  soluble  form. 

Cream  rises  extremely  slowly  in  sterilized  milk ;  in  six  hours 
only  one-tenth  of  the  amount  is  present  that  we  should  have 
found  in  raw  milk.  In  twenty-four  hours  the  bulk  of  the  cream 
will  rise,  but  the  total  quantity  will  be  less  than  that  from  the 
same  amount  of  raw  milk,  while  the  fat  percentage  will  be 
forty  as  against  thirty  in  fresh  cream. 

Partial  freezing  of  milk  causes  no  changes  in  any  of  the  con- 
stituents except  the  water.  Vieth  found  that  exposure  of  large 
quantities  of  milk  to  — 10°  C.  for  three  hours  caused  it  to 
freeze,  except  in  the  centre.  The  ice  consisted  of  two  layers, 
one  of  cream  and  the  other  of  skimmed  milk.  The  cream  con- 
tained 19.23  per  cent,  fat,  2.64  per  cent,  proteids,  3.33  per 
cent,  lactose,  and  0.52  per  cent.  ash.  The  milk  contained 
0.68  per  cent,  fat,  2.80  per  cent,  proteids,  3.95  per  cent,  lac- 
tose, and  0.60  per  cent.  ash.  The  liquid  portion  contained 
5.17  per  cent,  fat,  5.38  per  cent,  proteids,  7.77  per  cent,  lac- 
tose, and  1.18  per  cent.  ash.  These  figures  show  that  milk 
cannot  be  frozen  in  blocks,  from  which  pieces  can  be  cut  off 
and  melted  for  use,  without  its  composition  being  modified  to 
a  serious  extent. 

At  70°  C.  albumin  undergoes  change.  It  is  not  precipi- 
tated, but  is  converted  into  a  form  which  is  precipitated  by 
acid  magnesium  sulphate  and  other  precipitants  of  casein. 
Heating  above  70°  C.  alters  the  taste  and  smell  of  milk.  At 
about  80°  C.  certain  organized  principles,  the  nature  of  which 
is  not  fully  known,  undergo  a  change.  When  the  tempera- 
ture nears  100°  C,  calcium  citrate  is  deposited.  By  keep- 
ing at  this  temperature  for  some  time,  slight  oxidation  sets 
in  with  the  production  of  slight  traces  of  formic  acid  and 
marked  reduction  of  the  rotatory  power  of  lactose;  a  brown 
color  is  produced  at  the  same  time.  A  deposition  of  salt  and 
perhaps  of  albumin  also  takes  place  in  the  fat-globules,  which 


234  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

increases  their  mean  density,  causing  them  to  rise  slowly  to 
the  surface  when  the  milk  is  afterwards  cooled.  During  the 
heating  the  fat-globules  are  expanding,  and  may  sometimes 
coalesce.  It  is  not  known  how  far  the  heating  of  milk  affects 
its  digestibility.  Milk  which  has  been  heated  is  curdled  less 
readily  by  rennet  than  fresh  milk,  but  there  are  good  grounds 
for  the  view  that  this  is  due  to  the  deposition  of  calcium  salts 
rather  than  to  any  change  in  the  casein.  It  has  been  asserted 
that  sterilized  or  boiled  milk  is  digested  more  easily  than  raw 
milk,  but  this  may  be  due  to  the  fact  that  it  does  not  curdle  so 
easily  in  the  stomach  and  does  not  produce  so  firm  a  clot. 

The  Artificial  Digestion  of  Raw  and  Sterilized  Milk. 

Michel.101  The  author  carried  out  experiments  in  Budin's 
laboratory  with  the  artificial  digestion  of  raw  and  sterilized 
milk:  (1)  with  hydrochloric  acid  and  pepsin;  (2)  with 
pancreatin  in  neutral  or  alkaline  medium;  (3)  digestion  of 
the  curd  produced  by  the  action  of  the  lab-ferment  with  pepsin 
and  hydrochloric  acid;  (4)  digestion  of  the  curd  so  produced 
by  pancreatin;  (5)  complex  digestive  processes  with  lab, 
hydrochloric  acid,  pepsin,  and  pancreatin. 

In  his  experiments  the  polarimeter  was  used  to  estimate  the 
amount  of  peptones.  The  basis  employed  in  the  estimations  was 
the  ratio  of  the  peptones  to  the  total  nitrogen.  One  gramme 
of  nitrogen  represents  6.41  grammes  of  peptones  approxi- 
mately.   The  Kjeldahl  method  was  used. 

I.  Digestion  was  maintained  in  the  incubator  for  nearly 
eight  hours  at  40°  C.  Eaw  milk  furnished  18.75  grammes 
of  peptones;  sterilized  at  115°  C,  17.53  grammes,  the  former 
showing  somewhat  more  rapid  digestion. 

II.  Digestion  for  five  hours  gave  21.76  grammes  for  raw 
milk  and  24.64  grammes  when  the  milk  was  sterilized  at 
115°  C. 

III.  Digestion  in  the  incubator  for  three  and  a  half  hours 
at  40°  C.  gave  7.57  grammes  for  raw  milk  and  10.72  grammes 


STERILIZATION  AND   PASTEURIZATION.  235 

for  sterilized  milk.  When  the  digestion  was  kept  up  for  eight 
and  a  half  hours,  raw  milk  furnished  14.316  and  sterilized 
milk  twelve  grammes  of  peptones. 

IV.  The  curd  is  digested  much  more  rapidly  by  pancreatin 
when  sterilized  milk  is  administered  (28.22  grammes)  than 
when  we  give  raw  milk  (13.12  grammes). 

V.  The  digestion  of  raw  milk  by  lab-ferment,  pepsin,  and 
hydrochloric  acid  is  slower  in  the  first  three  hours  than  that 
of  sterilized  milk  (9.59  grammes  as  against  11.32  grammes) ; 
at  the  end  of  six  and  nine  hours  it  is  more  rapid,  giving  at 
the  latter  period  16.64  grammes  as  against  14.91  grammes. 
Further  digestion  with  artificial  pancreatic  juice  for  six  hours 
gave  21.76  grammes  of  peptones  for  raw  milk  and  24.57 
grammes  for  sterilized  milk. 

Digestion  of  the  Lactalbumins. 
101  Sterilized  milk  contains  almost  no  coagulated  albumin ; 
but  in  contact  with  the  acid  gastric  juice  the  albumin  of 
sterilized  milk  precipitates,  while  that  of  raw  milk  remains 
in  solution.  This  albumin,  whether  in  solution  or  not,  is 
of  long  and  difficult  peptic  digestion.  The  total  of  these 
experiments  shows  that  sterilization  does  not  injure,  but 
rather  increases  the  digestibility  of  the  milk  albuminoids. 
(?  Editors.) 

Filtration  through  Cotton,  and  Centrifugation. 

Marfan  believes  that  filtration  through  cotton,  to  be  effica- 
cious, must  slightly  alter  the  constitution  of  the  milk.  If 
germs  cannot  pass,  neither  can  all  of  the  milk  constituents. 
If  the  composition  is  not  modified,  neither  is  the  bacterial 
find. 

Seibert  has  proposed  filtration  through  moist  cotton  to  free 
milk  from  germs,  stating  that  the  milk  was  not  altered.  Va- 
riot  found  this  to  be  the  case,  but  that  the  impurities  passed 
through  as  well.     Heat  is  the  only  satisfactory  germicide. 


236  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

Seibert  (Archives  of  Pediatrics,  July,  1894)  asserted  that 
simple  filtration  through  a  half-inch  layer  of  compressed  ab- 
sorbent cotton  reduced  fhe  number  of  bacteria  from  one-half 
to  one-fourth  the  original  amount.  Kiliani  confirmed  his 
results.  Biedert  recommends  centrifugation  and  filtering  to 
remove  dirt. 

Schoenlein  found  that  after  centrifugation,  and  when  cream 
forms  by  the  gravity  process,  the  majority  of  the  bacteria  are 
found  in  the  cream,  very  few  in  the  dirt  which  is  thrown  out, 
and  the  remainder  in  the  skimmed  milk. 


CHAPTEK    X. 
WEIGHT   AND   GROWTH    OF   THE   INFANT. 

Monti."  The  body  weight  of  a  child  born  at  term  varies 
from  two  thousand  five  hundred  to  five  thousand  grammes,  sel- 
dom exceeding  the  latter  figures;  three  kilogrammes  may  be 
considered  the  average.  Twins  usually  weigh  only  from  two 
thousand  to  two  thousand  four  hundred  grammes ;  children  of 
primiparse  generally  from  one  hundred  and  seventy  to  one 
hundred  and  ninety  grammes  less  than  those  of  multipara. 
Within  a  few  hours  of  birth  a  loss  of  weight  occurs,  due  to 
the  evacuation  of  meconium  (from  sixty  to  ninety  grammes) 
and  the  passage  of  urine  (from  ten  to  fifteen  grammes),  evapo- 
ration from  the  lungs  and  skin,  and  to  the  deficient  intake  of 
food  during  the  first  days  of  life.  This  diminution  continues 
for  two  or  three  days,  and  is  made  up  within  from  five  to 
eight  days.  In  the  case  of  healthy  infants  at  the  breast  it 
amounts  to  from  one-fourth  to  one-sixteenth  of  the  body 
weight,  or  on  the  average  to  from  one  hundred  and  seventy 
to  two  hundred  and  twenty-two  grammes.  In  the  case  of  the 
artificially  fed  child  the  loss  in  weight  may  last  one  or  two 
days  longer.  The  poorer  the  development  or  the  less  the  body 
weight  of  an  infant  the  longer  will  be  the  loss  and  the  slower 
its  equalization.  In  premature  infants  this  is  especially  notice- 
able. Such  may  not  regain  their  weight  before  the  third  or 
fourth  week.  Premature  infants  who  are  artificially  fed  may 
lose  one-tenth  of  their  original  weight,  and  not  regain  it  in 
five  or  six  weeks;  they  should  therefore,  whenever  practicable, 
be  given  breast-milk. 

The  increase  in  weight  of  infants  at  the  breast  during  the 
first  year  follows  one  of  three  types. 

I.  In  a  large  series  of  cases  the  increase  in  weight  proceeds 
regularly  from  month  to  month;  this  was  first  observed  by 
Quetelet  and  Bouchaud. 

237 


238  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 


Body  weight  in 
.  Daily  increase.    Monthly  increase,    grammes.    Origi- 

I  '.  1-.1111.,,.-  ^i-ammna  113.1    WPlCrVlt     X9f>() 


One  month 

Two  months  . . . 
Three  months  .  . 
Four  months.  . . 
Five  months  . . . 
Six  months 
Seven  months  . . 
Eight  months  . . 
Nine  months. . . 
Ten  months .... 
Eleven  months  . 
Twelve  months. 


Grammes. 

Grammes. 

nal  weight  3250 
grammes. 

25 

750 

4000 

23 

700 

4700 

22 

650 

5350 

20 

600 

5950 

18 

550 

6500 

17 

500 

7000 

15 

450 

7450 

13 

400 

7850 

12 

350 

8200 

10 

300 

8500 

8 

250 

8750 

6 

200 

8950 

II.  Those  cases  where  the  increase  in  weight  is  progressive, 
diminishing  from  month  to  month,  but  in  which  the  increase 
in  weight  is  much  greater  during  the  first  four  months  and 
smaller  in  the  last  months  than  in  the  preceding  type. 


Fleischmann's  Table. 

Daily  increase. 

Monthly  increase. 

Body  weight  at  birth 

Age. 

Grammes. 

Grammes. 

3500  grammes. 

One  month 

35 

1050 

4550 

Two  months 

32 

960 

5510 

Three  months 

28 
22 

18 

840 
660 
550 

6350 

Four  months 

7010 

Five  months 

7560 

Six  months 

14 

420 

7980 

Seven  months 

12 

360 

8340 

Eight  months 

10 

300 

8640 

Nine  months 

10 
9 
8 
6 

300 
270 
240 
180 

8940 

Ten  months  .    

9210 

Eleven  months 

9450 

Twelve  months 

9640 

WEIGHT   AND   GROWTH   OF   THE   INFANT.  239 

III.  In  this  class  belong  those  cases  where  the  body  weight 
does  not  increase  regularly,  but  by  fits  and  starts,  and  in  which 
the  greatest  increase  frequently  occurs  in  the  second  or  the 
fourth  month  and  diminishes  after  that  time. 

The  following  table  is  taken  from  Hahner,  the  child  weigh- 
ing three  thousand  one  hundred  grammes : 


Daily  increase. 

Age.  _ J 

Grammes. 

One  month 24. 5 

Two  months 36.5 

Three  months 20.5 

Four  months 15.6 

Five  months 22.3 

Six  months 10.8 

Seven  months 22.5 

Eight  months 14.0 

Nine  months 9.0 

Ten  months 10.3 

Eleven  months 16.3 

Twelve  months 10.0 


Monti,  on  the  basis  of  his  own  experience,  considers  that 
the  first  type  is  characteristic  of  children  who  have  the  nor- 
mal average  original  weight  and  are  fed  regularly.  The  second 
type  occurs  in  children  who  have  higher  original  weight  and 
are  fed  plentifully.  The  third  type  seems  to  occur  only  where 
the  child  has  been  overfed.  The  original  weight  may  be  normal 
or  above  it. 

From  this  it  appears  that  the  body  weight  of  a  child  doubles 
in  the  first  five  months  and  triples  at  the  end  of  the  first  year. 
The  data  here  presented  are  of  course  only  schematic.  The 
conditions  affecting  the  individual  child,  its  hygienic  surround- 
ings, the  diet  of  the  mother,  correct  or  incorrect  observance 


nthly  increase. 
Grammes. 

Body  weight. 
Grammes. 

735 

3835 

1095 

4930 

610 

5540 

470 

6010 

670 

6680 

325 

7005 

675 

7680 

420 

8100 

270 

8370 

310 

8680 

490 

9170 

300 

9470 

240  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

of  rules  of  feeding,  etc.,  will  all  give  a  different  weight-curve, 
which,  notwithstanding  the  above  conditions,  must  be  consid- 
ered normal.  Camerer  gives,  on  the  basis  of  weighings  of 
fifty-seven  children  at  the  breast,  with  an  original  weight  of 
three  thousand  four  hundred  and  fifty  grammes  and  over,  the 
following  tables,  representing  the  weight  in  grammes  at  the 
end  of  the  following  weeks. 

I. 

2  4  8         12        16        20    weeks 

3400    3490    3890    4680     5410     6090    6650  grammes 

32        36        40        44        48        52    weeks 
7570     7990    8400    8580     9020    9300    9890  grammes 

Daily  Increase  in  Grammes. 
4-8  8-12        12-16        16-20  weeks 

28  26  24  20     grammes 

28-32        32-36        36-40        40-52  weeks 
15  14  7  15     grammes 

In  children  whose  weight  at  birth  is  subnormal  the  daily 
gain  is  usually  less,  and  it  approximates  that  of  normal  chil- 
dren only  when  it  has  regained  the  normal  height  correspond- 
ing to  a  child  of  that  age. 

Fleischmann  was  the  first  to  notice  the  constant  rise  and 
fall  in  body  weight;  Vierordt  and  Malling-Hansen  have  con- 
firmed Fleischmann's  observations.  Monti  is  also  of  the  opin- 
ion that  one  must  not  assume  for  every  child  during  the  first 
year  a  steady  increase  in  weight.  The  conditions  of  the  day 
and  year,  the  hygienic  surroundings,  the  mother's  diet,  and 
anything  affecting  the  child's  environment  must  be  considered 
in  order  to  avoid  error. 

The  increase  in  weight  is  quite  different  in  children  on  mixed 
feeding.  They  show  variations  and  irregularities  which  appear 
in  the  following  table : 


At  birth 

1 

3450 

3400 

24 

28 

7130 

7570 

II. 

1-2 

2-4 

3 

29 

20-24 

24-28 

17 

15 

WEIGHT   AND    GROWTH    OF   THE   INFANT. 


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242  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

In  artificially  fed  children  the  gain  in  weight  during  the 
first  year  is  usually  less  than  in  children  at  the  breast  or  in 
those  getting  mixed  feeding. 

According  to  the  condition  of  the  digestive  tract  and  the 
degree  of  absorption,  the  gain  in  weight  of  artificially  fed 
infants  is  subject  to  manifold  variations  and  disturbances. 
Monti's  personal  experience  leads  him  to  conclude  that  in 
artificially  fed  children  the  gain  is  seldom  normal  or  reg- 
ular. 

Eussow  has  found  that  the  weight  of  the  hand-fed  infant 
is  not  tripled  before  its  second  year.  This  difference  is  also 
observed  in  the  later  years  of  life,  so  that  breast-fed  infants 
in  their  fourth  year  weigh,  on  the  average,  two  thousand 
grammes  more  than  artificially  fed  infants.  The  same  author 
gives  the  following  table  of  the  average  gain  in  weight  of 
children  fed  on  cow's  milk  plus  starchy  foods:  fifteen  days, 
2900  grammes;  three  months,  4089  grammes;  six  months, 
4744  grammes ;  eight  months,  5254  grammes ;  twelve  months, 
6128  grammes;  two  years,  7430  grammes;  four  years,  twelve 
kilogrammes;  eight  years,  eighteen  and  three-tenths  kilo- 
grammes. 

Camerer  states  that  artificially  fed  children  are  backward 
in  their  development  during  the  first  half-year  and  weigh  about 
one  kilogramme  less  than  breast-fed  children  of  the  same  age. 
Monti  takes  exception  to  Camerer's  statement  that  at  the  end 
of  the  first  year  hand-fed  children  have  an  equal  weight  with 
breast-fed  children.  He  thinks  that  this  occurs  only  excep- 
tionally. 

Weighings  should  be  made  every  eight  days  at  a  fixed  hour 
during  the  first  year.     Daily  weighings  give  uncertain  results. 

Cautley.38  Three  kilogrammes  (six  and  a  half  pounds) 
is  a  fair  average  weight  at  birth,  though  often  exceeded. 
There  is  a  decided  loss  in  weight  during  the  first  few  days 
of  life,  which  has  been  estimated  by  Haake,  Quetelet,  and 
Winckel  at  about  half  a  pound.     The  prolonged  presence  of 


WEIGHT   AND   GROWTH    OF   THE   INFANT.  243 

colostrum  in  mother's  milk  may  induce  a  loss  in  infants  who 
would  otherwise  gain.  The  passage  of  meconium  and  urine, 
the  excretion  of  water  by  the  skin  and  the  expired  air,  the 
falling  off  of  the  cord,  and  the  lack  of  food,  all  account  for 
what  may  be  termed  the  physiological  loss,  although  this  does 
not  invariably  occur. 

Stated  roughly,  the  initial  weight  is  doubled  at  five  months 
and  trebled  at  fifteen  months.  Kotch  gives  the  following 
figures  based  on  an  original  weight  of  from  three  thousand 
to  four  thousand  grammes.  From  birth  to  five  months  the 
average  gain  per  day  will  be  twenty  to  thirty  grammes,  from 
five  to  twelve  months  the  average  gain  per  day  will  be  ten 
to  twenty  grammes,  and  at  one  year  a  child  ought  to  weigh 
nine  and  a  half  kilogrammes  (20.9  pounds).  Cautley  deduces 
an  average  table  from  those  of  Sutils,  Schmid-Monnard, 
Hahner,  Kotch,  and  others.  He  estimates  thirteen  months 
of  twenty-eight  days  each;  the  figures  represent  the  weekly 
gain: 

Ounces.  Ounces. 

One  month 6  Eight  months 3J 

Two  months 7  Nine  months 2£ 

Three  months 6  Ten  months 2\ 

Four  months b\  Eleven  months 2 

Five  months    5  Twelve  months 2 

Six  months \.\  Thirteen  months \\ 

Seven  months 4 

This  amounts  to  a  gain  of  about  six  ounces  a  week  during 
the  first  three  months,  five  ounces  a  week  for  the  second  three 
months,  three  ounces  a  week  for  the  third  three  months,  and 
two  ounces  a  week  for  the  remainder  of  the  year. 

The  increase  of  weight  does  not  take  place  with  such  abso- 
lute regularity  as  indicated  in  the  table,  either  in  bottle-fed 
or  breast-fed  infants.  To  a  certain  extent  the  rate  of  gain 
is  affected  by  the  period  of  the  year,  attaining  its  maximum 


244  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

between  July  and  October.  Sunlight  and  fresh  air  are  also 
beneficial  and  increase  the  rate  of  growth.  The  gain  is  not 
invariably  proportionate  to  the  initial  weight.  Infants  ab- 
normally small  at  birth  sometimes  gain  with  much  greater 
rapidity  than  those  of  a  much  larger  initial  weight. 

J.  P.  Crozer  Griffith,172  in  an  article  in  the  New  York 
Medical  Journal  for  March  4,  1899,  mentions  the  difficulties 
encountered  in  calculating  the  normal  variations  in  weight 
during  the  first  two  years  of  life:  the  influence  of  feeding, 
the  amount  of  food,  defecation  and  urination,  perspiration, 
and  even  the  ordinary  metabolic  changes  occurring  during 
sleep.  The  child's  weight  is  distinctly  greater  at  night  than 
in  the  morning.  It  seems  impossible  to  apply  the  precise 
algebraic  rule  of  Kaudnitz,  based  on  a  given  age.  The  best 
that  can  be  done  is  to  determine  the  general  average  in  a 
large  number  of  cases  and  to  represent  it  graphically  in  the 
form  of  a  weight-chart. 

In  generalizing  methods  a  number  of  infants  of  a  certain 
age  are  weighed.  Another  group,  perhaps  differing  in  number 
and  age,  are  also  weighed.  The  results  are  apt  to  be  deceptive 
and  do  not  represent  true  or  normal  conditions. 

"  In  Lorey's  investigations,  weighings  of  five  hundred  and 
sixty-five  children  were  made  by  this  method.  In  spite  of 
this  large  number,  it  is  quite  evident  that  the  irregularities 
which  his  weight-curves  show,  especially  in  the  second  year, 
do  not  represent  the  actual  condition  to  be  expected  in  the 
average  child.  In  the  combined  curve  for  both  sexes,  for 
the  second  year,  it  appears  that  children  at  twenty-one  months 
weigh  less  than  they  do  at  twenty  months,  and  again  less 
at  twenty-four  than  they  do  at  twenty-three  months.  This 
certainly  does  not  represent  the  true  state  of  the  case.  Lorey 
makes  no  claim  that  his  figures  yield  any  statistical  results, 
although  based  on  so  many  cases. 

"  The  individualizing  method  is  better.  The  weighings  of 
one    child    are    recorded    at   frequent    and    regular    intervals 


CHART   I. 

WEIGHT  IN  FIRST  10  DAYS 


CO 

5 
< 

K 
O 

DAYS 

0 

i 

2 

3 

4 

5 

6 

7 

8 

9 

10 

to 

in 

N 
O 

12 
10 

3,459 

3,402 

8 

* 

3,345 

6 

\ 

\ 

3,289 

4 

\ 

\ 

-GREG 

ORY 

\ 

s 

3,232 

2 

v 

A 

^X 

-KEZM/ 

RSKY 

\ 

/ 

V*' 

\ 

^ 

> 

HOLT- 

3,175 

7 

\ 

/ 

/• 

V^ 

~-J^ 

xx' 

3,119 

14 

I 

-COMB 

r 
\ 

/ 

/ 

3,062 

12 

\ 

/, 

> 

I 

^ 

3,005 

10 

\ 

V 

\i 

f 

2,948 

8 

V 

// 

\ 

^jl 

2,892 

6 

v^ 

ir 

V 

^-*AA 

KE 

2,835 
2,778 

2 

A 

2,722 

14 

—f 

CHART   II. 

GAIN  IN  WEIGHT.- LOREY 


MONTHS 

1 

2 

3 

4 

5 

a 

7 

3 

9 

10 

11 

12 

13 

14 

15 

16 

17 

18 

19 

20 

21 

22 

23 

24 

12,000 
1 1 ,000 

1 0,000 

9,000 

8,000 

to 

2 

<  7,000 

O 

6,000 
5,000 
4,000 

3,000 

2,000 

A 

A 

/ 

/i 

I 

1 

\ 

ft 

/ 

V 

i 

I 
I 

1 

I 

f 

1 

/ 

A 

V 

I 

/ 

\ 

/ 

1       i 
\     . 
\    , 
I. 

t 

^ 

/ 

X 

y 

^ 

'*" 

/ 

'J 

1 

/  / 
/  / 

1 I 

1 

-  B( 
-Gl 

jYS 
RLS 

> 

WEIGHT   AND   GROWTH    OF   THE   INFANT.  245 

throughout  its  infant  life,  and  comparison  is  made  with  a 
large  number  of  similar  records  of  individual  cases.  The 
mean  weights  and  the  average  rate  of  increase  for  different 
periods  of  the  child's  life  can  readily  be  computed. 

"  It  has  been  of  interest  to  me  to  compare  the  various  tabu- 
lated observations  which  have  been  made  in  the  effort  to 
determine  the  growth  of  the  child  during  the  first  two  years 
of  life.  Perhaps  the  oldest  and  one  of  the  most  quoted  tables 
of  growth  is  that  of  Quetelet,  but  this  is  more  ideal  than 
actual,  and,  as  plotted  by  Fleischmann,  gives  a  straight  line 
rather  than  the  curve  which  represents  the  actual  condition 
of  affairs  as  now  understood.  The  straight  line  results  from 
the  assumption  that  the  rate  of  growth  is  the  same  for  all 
periods  of  the  first  year. 

"  A  second  much-quoted  estimation  is  that  of  Bouchaud. 
Although  his  observations  were  made  by  the  individualizing 
method,  he  has  rounded  off  his  figures  to  such  an  extent  that 
his  final  table  of  growth  is  much  too  schematic.  The  plotted 
curve  is,  however,  a  more  accurate  representation  than  that  of 
Quetelet,  although  it  gives  a  rate  of  growth  lower  than  may  be 
expected  of  the  average  healthy  breast-fed  infant. 

"A  table  of  weight,  constructed  by  Fleischmann  by  the 
individualizing  method  applied  to  fifteen  breast-fed  children, 
is  often  referred  to.  I  have  plotted  the  curve  derived  from 
these  figures  in  Chart  II.  It  shows  the  rapidity  of  growth 
of  the  first  months  and  the  diminishing  rate  during  the  suc- 
ceeding months. 

"Recently  a  useful  curve  has  been  published  by  Holt,  con- 
structed apparently  by  the  individualizing  plan. 

"  One  of  the  most  careful  studies  of  the  subject  is  that 
of  Camerer.  This  observer  has  followed  by  the  individualizing 
method  the  rate  of  growth  of  a  large  number  of  children 
during  the  first  year  of  life,  has  studied  the  similar  obser- 
vations of  Fleischmann,  Vierordt,  and  others,  and  has  pub- 
lished several  tables  and  curves  which,  on  the  whole,  appear 


246  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

to  be  the  most  valuable  we  yet  possess.  Attention  has  been 
paid  to  the  variations  in  initial  weight  and  influence  of  these 
upon  the  later  weights,  and  also  to  the  nature  of  the  food, 
whether  human  milk  or  cow's  milk.  Even  Camerer's  curves, 
however,  have  certain  irregularities  which  prevent  their  being 
taken  as  types, — for  which,  indeed,  they  are  not  intended. 
In  Chart  II.  I  have  plotted  the  curve  of  his  figures  for  breast- 
fed children  with  an  initial  weight  of  over  seven  hundred 
and  fifty  grammes  (six  pounds  and  one  ounce).  Camerer  also 
gives  some  estimations  of  the  rate  of  growth  during  the  second 
year  (Chart  II.).  Another  observation  upon  growth  in  the 
second  year  is  that  of  Lorey,  already  referred  to.  In  Chart 
II.  I  have  combined  his  chart  for  boys  and  girls  respectively 
during  the  second  year,  thus  eliminating  some  of  the  irregu- 
larities. In  all  the  curves  represented  in  Chart  II.  all  figures 
originally  in  the  metric  system  have  been  reduced  to  avoir- 
dupois weight  for  the  convenience   of  comparison. 

"The  following  weight-chart  (IV.)  has  been  constructed  in 
the  effort  to  represent  as  nearly  as  possible  the  average  rate  of 
growth  of  healthy  breast-fed  children.  Although  to  a  certain 
extent  schematic,  as  any  averaging  chart  of  this  nature  must 
necessarily  be,  it  is,  I  think,  as  accurate  as  can  be  expected 
of  any  one  suited  for  practical  purposes.  It  has  been  made 
after  a  careful  study  of  most  of  the  available  published  data, 
although  it  follows  Camerer's  curve  more  nearly  than  any 
other. 

"  The  fact  that  it  is  so  often  necessary  to  record  the  weight 
of  poorly  developed  children  during  the  second  year  necessi- 
tated the  representing  in  this  chart  of  the  continuous  growth 
during  the  first  two  years  of  life.  The  line  passing  obliquely 
through  it  represents,  of  course,  the  rate  of  growth  of  healthy 
breast-fed  children.  Bottle-fed  babies,  as  a  class,  fall  below 
this  weight,  yet  by  no  means  necessarily  so.  There  is  also 
some  difference  in  weight  depending  upon  sex,  boys  being 
generally  heavier  than  girls.     This  difference  may,  however, 


WEIGHT   AND   GROWTH    OF   THE   INFANT.  247 

be  ignored  in  this  connection.  Each  horizontal  line  repre- 
sents a  difference  of  four  ounces.  A  gain  of  two  ounces  or 
even  less  can  be  indicated  by  marking  between  the  lines. 
The  weight  should  be  taken  weekly  and  recorded  by  dots  con- 
nected by  a  line,  as  in  a  temperature-chart.  For  convenience, 
the  figures  at  the  top  show  not  only  the  weeks,  but  the 
months  as  well.  In  order  to  prevent  the  chart  from  becoming 
of  an  unmanageable  size,  the  portion  for  the  second  year — 
since  this  will  be  needed  less  frequently — has  been  narrowed 
in  such  a  way  that  the  space  for  four  weeks  is  of  the  same 
breadth  as  that  for  two  weeks  during  the  first  year.  Tfris 
necessarily  distorts  the  proper  position  of  the  plotted  curve, 
and  gives  the  erroneous  impression  to  the  eye  that  the  child 
grows  as  rapidly  during  the  second  year  as  during  the  first. 
It  is  evident  that  if  the  spaces  for  the  years  were  of  equal 
breadth,  the  curve  for  the  second  year  would  be  very  much 
nearer  a  horizontal  line.  For  practical  purposes  this  distor- 
tion of  the  curve  is  of  no  moment,  since  its  actual  relation 
to  the  figures  is  unaltered. 

"  There  are  a  few  matters  remaining  to  which  brief  refer- 
ence must  still  be  made.  First,  the  birth-weight  assumed 
(seven  and  three-fourths  pounds)  is  somewhat  more  than  that 
given  by  many  writers,  yet  it  agrees  practically  with  the  sta- 
tistics of  Fleischmann,  as  also  with  those  of  Camerer  for  many 
of  his  cases.  Should  a  child  at  birth  weigh  much  less  than  this, 
it  is  to  be  expected  that  the  rate  of  growth  will  be  very  much 
the  same.  This  will  give  a  curve  slightly  below  that  of  the 
chart.  But  a  child  who  weighs  over  seven  pounds  at  birth 
may  be  expected  to  reach  the  full  normal  weight  by  the  age 
of  one  year. 

"Then  as  to  the  loss  in  weight  which  the  child  suffers 
after  birth  before  its  regular  gain  begins.  Although  this  does 
not  necessarily  take  place,  yet  its  occurrence  is  the  rule  and 
may  be  considered  physiological.  This  was  shown  by  the  in- 
teresting experiments  of  Ingersley,  who  allowed  sixteen  chil- 


248  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

dren  immediately  after  birth  to  be  suckled  regularly  by  women 
who  had  been  confined  a  few  days  before.  The  remarkable 
fact  was  noticed  that  the  children  showed  not  only  a  greater 
but  a  more  prolonged  loss  of  weight  than  the  average. 

"  There  have  been  various  estimations  made  of  the  degree 
and  duration  of  loss.  Some  of  these  I  have  depicted  in  Chart 
III.,  including  the  observations  of  Gregory,  Kezmarsky,  Holt, 
Comby,  and  Haake.  In  all  cases  statistics  in  the  metric 
system  or,  in  the  case  of  Haake,  in  the  old  German  system 
of  weights  have  been  changed  into  pounds  and  ounces  avoir- 
dupois. The  curves  of  Gregory  and  Kezmarsky,  it  will  be 
noticed,  run  much  together.  The  first  was  based  upon  obser- 
vations made  on  thirty-three  and  the  second  on  thirty-two 
healthy  breast-fed  children.  Kezmarsky  explains  the  greater 
duration  of  loss  in  his  cases  and  the  slower  gain,  as  compared 
with  Gregory's,  on  the  ground  that  the  children  under  his 
care  were  not  nursed  with  the  regularity  which  was  desirable. 
In  Gregory's  they  have  nearly  regained  the  normal  weight 
by  the  seventh  day;  Kezmarsky's  fall  much  short  of  this. 
These  two  curves  are  largely  in  accord  with  the  observations 
of  Winckel,  and  seem  to  represent  the  experience  of  most 
investigators.  The  curve  representing  the  table  of  Comby 
seems  to  be  largely  schematic.  I  cannot  find  on  what  actual 
observations  it  is  based.  The  curve  of  Holt  represents  his 
experience  with  a  hundred  healthy  breast-fed  children.  It 
differs  from  the  others  in  the  greater  degree  of  loss  of  weight, 
which  equals  ten  ounces  (two  hundred  and  eighty-four 
grammes).  This,  however,  is  in  accord  with  the  observations 
of  Townsend  on  the  records  of  two  hundred  and  thirty-one 
breast-fed  children  in  the  Boston  Lying-in  Hospital.  Here 
the  average  loss  was  two  hundred  and  seventy-nine  grammes 
(9.8  ounces).  I  presume,  however,  that  children  suffering 
from  illnesses  were  not  excluded  in  making  the  computation. 
The  observations  of  Haake  on  one  hundred  healthy  breast-fed 
children,  as  shown  in  the  curve,  not  only  give  a  loss  which 


CHART   III. 


MONTHS 
WEEKS     4 

8J    12|    16 1  20  |   24  |  28  [82  (36    |40     |44    | 

18   »    5 

3      1*4 

6  60|    6"! 

i'5    i'e 

|    68  |75 

1*7     1'8     1*9     2*0    2J1     2&     2 

1  76   1 80   J  84   [88    |92    ,96  1 

3     M 

'0   1 

LBS. 

27 

/ 

25 

/ 

/* 

*" 

/ 

/ 

\ 

23 
22 

C2 

/ 

s 

/ 

c- 

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21 

F- 

Q 

V 

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B 

18 

'-/ 

/- 

-L 

s 

£ 

-H 

16 

'A 

V 

r 

',< 

14 

''/ 

/ 

/ 

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12 
11 
10 

// 

/ 

/ 

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/// 

B 

6 

Weight-curves  of  C— Camerer.  <V- Camerer,  second  year.   F— Fleischmann.   H— Holt. 
L— Lorey.    B— Bouchaud.    Q— Quetelet. 


CHAET   IV. 

infant's  weight-chart. 

(Designed  by  J.  P.  Crozer  Griffith,  M.D.,  Clinical  Professor  of  Diseases  of  Children  in 
the  University  of  Pennsylvania.) 


Name-- 


Months     1 
Weeks    1    3  |s ■  1   f 9  11 13  1517J  19  2l| 


Date  of  birth-- 


10        11       12  13  14  15   16  17  18  19  20  21 22  23  24 
45  47U9  5lj  5G  CO1  641  ggj  72!  76J  goU  [sS^WU 104 


Weeks   1    35    7    9  11131517  19  2123  25  27  293133  35  37  39  4143  45  47  49  51    56  60  64  68  72  76  80  84  88  92  96100104 


WEIGHT   AND   GROWTH    OF   THE   INFANT.  249 

is  less  than  that  usually  accepted  as  the  common  one,  being 
but  a  hundred  and  sixty-three  grammes  (5.75  ounces),  but 
also  an  initial  weight  lower  than  the  average. 

"  According  to  Fleischmann,  who  has  made  a  careful  study 
of  various  writers'  estimations,  the  average  total  loss  equals 
two  hundred  and  twenty-two  grammes  (7.8  ounces).  The  dura- 
tion of  loss  is  from  two  to  three  days,  and  sometimes  longer. 
The  total  loss  equals  about  one-fourteenth  or  one-fifteenth  of 
the  initial  body  weight.  Increase  in  weight  begins  on  the 
second  to  the  fourth  day,  but  the  original  weight  is  seldom 
regained  before  the  eighth  or  the  ninth  day  or  even  not  before 
the  tenth  day.  Chart  IV.  shows  the  approximate  loss  existing 
at  the  end  of  the  first  week,  but  not  the  greater  loss  which  has 
taken  place  before  this  date. 

"  Lastly,  the  variation  in  the  weight-curve  of  any  infant 
which  a  weight-chart  will  show  must  be  borne  in  mind.  Not 
only  will  there  be  a  variation  dependent  upon  the  fulness 
of  the  stomach,  bladder,  and  bowels,  as  already  stated,  but 
there  is  a  variation  which  does  not  rest  upon  these  factors 
and  yet  which  cannot  be  called  pathological.  For  instance, 
it  not  infrequently  happens  that  a  baby  goes,  it  may  be,  a 
week  without  a  gain  in  weight,  or  even  shows  a  loss,  and 
yet  cannot  be  called  ill.  Yet  such  a  condition  should  always 
arouse  watchfulness. 

"  The  value  of  the  systematic  recordings  of  an  infant's  weight 
scarcely  needs  to  be  emphasized.  Every  physician  especially 
interested  in  diseases  of  children  fully  recognizes  it,  for  he 
knows  that  often  a  failure  to  gain,  even  before  the  child  shows 
to  the  eye  any  ailment  whatever,  may  be  the  sign  that  some 
form  of  illness  is'  present  or  that  the  child  is  underfed.  The 
weight-chart  is  even  more  valuable  than  the  temperature- 
chart  in  the  case  of  infants.  The  weighing,  too,  is  such  a 
simple  matter  that  there  is  no  excuse  for  a  failure  to  have 
it  carried  out  by  the  mother  at  least  once  a  week,  and  where 
a  change  in  the  method  of  feeding  is  being  made,  twice  a 


250  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

week.  Good  spring  scales  showing  ounces  are  not  expensive, 
or  a  steelyard  or  ordinary  kitchen  scales  with  weights  will 
answer;  but  best  are  some  of  the  standing  spring  scales  fitted 
with  an  oblong  basket  or  a  scoop,  and  which  are  to  be  devoted 
solely  to  the  weighing  of  the  baby. 

"  It  is  of  course  understood  that  the  weight  recorded  is  that 
of  the  child  undressed.  If  undressing  at  every  weighing  is 
inconvenient,  the  child  may  be  weighed  when  dressed  and 
then  when  undressed,  and  the  weight  of  the  clothes  deducted. 
At  subsequent  weighings,  then,  it  is  only  necessary  to  see  that 
the  clothing  is  exactly  similar,  and  undressing  will  not  be 
required/' 

Metabolism. 

Catjtley.38  "  The  child  requires  more  food  in  proportion 
to  its  body  weight  than  the  adult.  The  relationship  of  the 
different  constituents  of  its  diet  to  one  another  also  varies 
because  of  the  extra  need  of  heat-producing  food  during  the 
early  months  of  life,  to  counterbalance  the  deficient  heat  pro- 
duction from  lack  of  muscular  energy  and  the  greater  loss  of 
heat  by  the  skin  proportionately  to  the  bulk  of  the  body. 

"  Practically  all  foods  may  be  considered  to  consist  of  five 
proximate  principles :  water,  proteids,  carbohydrates,  fats,  and 
salts. 

"  Water. — Though  water  is  not  primarily  a  source  of  energy 
nor  nutritious  in  the  ordinary  sense  of  the  word,  it  is  never- 
theless essential  to  life  and  constitutes  more  than  half  the 
entire  body  weight.  Physiological  activity  of  the  cell  depends 
upon  a  due  supply  of  water.  Proportionately  to  its  weight, 
the  infant  requires  much  more  than  the  adult;  the  relation- 
ship of  the  body  surface  to  the  body  weight  being  considerably 
greater,  therefore  the  loss  of  moisture  by  the  skin  is  more  in 
proportion. 

"  To  a  large  extent  water  assists  in  digestion ;  it  increases 
the  secretion  of  pepsin  and  hydrochloric  acid  (Jacobi)  and 
thus  aids  in  proteid  digestion ;  it  is  of  great  value  as  a  solvent 


WEIGHT   AND   GROWTH   OF   THE   INFANT.  251 

and  diluent  of  food  substances  and  thus  assists  in  absorption 
from  the  alimentary  canal;  it  promotes  the  activity  of  the 
circulation  of  fluids,  increases  cell  metabolism,  and  aids  elimi- 
nation; as  a  diluent  of  the  intestinal  contents  it  helps  to 
prevent  constipation. 

"  Proteid  is  the  form  of  food  in  which  nitrogen  is  supplied 
to  the  body.  Nitrogenous  matter  is  essential  to  the  structure 
of  protoplasm  and  enters  into  the  structure  of  every  cell.  All 
the  tissues  of  the  body  are  formed  by  cells  or  modifications 
of  cells,  and  consequently  the  child  requires  even  more  pro- 
teid, in  proportion  to  its  weight,  than  the  adult,  who  has  only 
to  maintain  equilibrium  of  tissue,  whereas  the  infant  has  to 
provide  for  the  building  up  of  new  tissue.  An  adult  man  of 
sixty-seven  kilogrammes  weight  requires  about  a  hundred 
grammes  of  proteid  daily.  An  infant  of  6.7  kilogrammes  (the 
weight  of  an  infant  about  six  months  old)  takes  one  thousand 
grammes  of  milk  daily,  containing  twenty  grammes  of  pro- 
teid ;  much  more  proportionately  than  the  adult.  So,  too,  the 
growing  child  requires  a  free  supply  of  proteid  food,  more  pro- 
portionately than  the  adult,  and  yet  very  commonly  gets  less. 

*  Animal  proteids  are  more  digestible  than  vegetable  pro- 
teids,  and,  as  a  rule,  the  more  they  are  altered  by  cooking 
the  more  difficult  of  digestion  they  become.  The  chief  animal 
proteids  are  the  myosin  of  meat,  the  casein  and  lactalbumin 
of  milk,  and  the  various  proteids  of  blood.  All  the  proteids 
taken  into  the  stomach  are  not  necessarily  digested  and  as- 
similated; even  in  an  infant  at  the  breast  a  considerable  pro- 
portion of  the  proteids  may  be  found  in  the  fasces. 

"When  the  proteids  of  the  food  are  deficient,  the  child 
becomes  anaemic,  languid,  debilitated,  and  short  of  breath  on 
exertion.  The  muscles  are  soft  and  flabby  and  the  child  ceases 
to  grow.  Too  great  a  proportion  of  proteids,  on  the  other 
hand,  leads  to  indigestion,  colic,  and  constipation,  especially 
when  the  casein  is  in  excess. 

"Fat. — The  two  great   food-stuffs   for  the  production   of 


252  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

heat  are  the  fats  and  the  carbohydrates,  and  of  the  two  the 
fat  is  more  valuable  by  virtue  of  the  large  amount  of  carbon 
which  it  contains.  Fats  are  much  poorer  in  oxygen  and 
richer  in  carbon  and  hydrogen  than  the  carbohydrates,  and 
therefore  their  heat  value  is  proportionately  greater.  Heat 
is  essential  to  life,  and  all  the  vital  processes  are  more  active 
at  the  temperature  of  the  body  than  at  a  lower  temperature. 
This  is  more  especially  the  case  with  the  muscular  and  nervous 
systems.  Although  we  have  no  proof  that  the  fat  in  the  tissues 
is  formed  from  the  fat  taken  in  as  food,  it  is  well  known  that 
the  fat  stored  up  is  soon  drawn  upon  if  the  food  is  deficient, 
and  hence  the  tissues  may  suffer  indirectly.  An  infant  of 
6.7  kilogrammes  takes  in  its  milk  forty  grammes  of  fat, 
whereas  an  adult  weighing  ten  times  as  much  does  not  re- 
quire more  than  one  hundred  grammes.  The  reason  for  this 
is  that  the  infant  cannot  maintain  its  bodily  temperature  by 
exercise  in  the  same  way  as  the  adult. 

"  Attempts  have  been  made  to  remedy  deficiency  of  fat  in 
the  infant's  diet  by  the  addition  of  carbohydrate  food.  Such 
a  substitution  is  theoretically  sound  if  fat  is  regarded  as  a 
source  of  heat  only,  and  the  proportion  of  additional  carbo- 
hydrate required  for  this  purpose  can  readily  be  calculated. 
Clinical  results  prove,  however,  that  such  a  substitution  is  un- 
satisfactory, and  that  carbohydrates  cannot  replace  fat  to  the 
advantage  of  the  child.  The  best  evidence  of  this  is  the  preva- 
lence of  rickets  among  infants  brought  up  on  sweetened  con- 
densed milk. 

"  Artificial  mixtures,  as  usually  ordered,  rarely  contain  such 
an  excess  of  fat  as  to  cause  gastro-intestinal  disturbances. 
Such  results  do  occasionally  occur  in  infants  brought  up  at 
the  breast  where  the  mother's  milk  contains  abnormally  high 
percentages  of  fat.  Generally  at  the  same  time  there  is  an 
excessive  proportion  of  proteids,  so  that  it  is  difficult  to  ascer- 
tain to  which  excess  the  digestive  disturbance  is  due. 

"Too  free  an  administration  of  fat  in  the  food  may  give 


WEIGHT   AND   GROWTH   OF   THE   INFANT.  253 

rise  to  a  variety  of  diarrhoea  described  by  the  Germans  as 
'fat  diarrhoea/  and  characterized  by  the  presence  of  a  large 
quantity  of  fat  in  the  stools.  It  is  usually  associated  with 
simple  intestinal  catarrh. 

"  Sugar. — Carbohydrates  are  of  value  for  the  production 
of  heat  and  as  a  source  of  muscular  energy.  The  infant 
weighing  6.7  kilogrammes  takes  about  seventy  grammes  of 
carbohydrate  in  its  milk;  the  adult  of  ten  times  the  weight 
requires  about  two  hundred  and  forty  grammes  and  more  in 
proportion  to  the  amount  of  muscular  work  he  performs. 

*  Infants  at  the  breast  practically  never  suffer  from  defi- 
ciency of  carbohydrate  food,  the  percentage  in  human  milk 
varying  within  comparatively  small  limits;  in  artificial  feed- 
ing there  is  more  commonly  an  excess. 

"  Nearly  all  the  patent  foods  and  condensed  milk  on  the 
market  contain  an  excess  of  carbohydrates,  generally  in  the 
form  of  starch  or  cane-sugar.  Almost  all  the  infants  fed  upon 
these  foods  become  fat,  flabby,  unwieldy,  and  rachitic.  In- 
testinal disturbances  are  also  frequently  induced. 

"  Salts. — Bunge  was  the  first  to  establish  the  remarkable 
fact  that  the  percentages  of  salts  in  the  ash  of  the  new-born 
animal  are  practically  the  same  as  the  percentages  of  ash  in 
mother's  milk.  Certain  exceptions  are  noticeable  and  im- 
portant. The  ash  of  the  milk  contains  more  potassium  and 
less  sodium  salts,  which  may  be  explained  by  the  fact  that,  as 
the  animal  grows,  there  is  a  relative  increase  in  the  muscles 
which  are  rich  in  potassium  and  a  diminution  in  the  carti- 
lages which  are  rich  in  sodium. 

"Another  important  difference  is  the  percentage  of  iron. 
The  proportion  of  iron  in  the  ash  of  the  new-born  animal  is 
very-  much  greater  than  in  the  ash  of  mother's  milk.  The 
latter  deficiency  is  counteracted  by  the  young  animal  storing 
up  iron  in  its  liver  previous  to  its  birth.  Bunge  has  found 
that  the  proportion  of  iron  in  the  ash  of  animals  of  the  same 
litter  diminishes  with  the  increase  in  the  growth  of  the  ani- 


254  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

mal,  showing  that  this  previously  stored-up  iron  is  required  to 
make  up  for  the  deficiency  of  iron  in  the  mother's  milk. 

"  Sodium  Chloride. — Cow's  milk  contains  so  much  more 
sodium  chloride  than  mother's  milk  that  it  is  not  necessary 
to  add  common  salt  to  cow's  milk  in  artificial  feeding.  [The 
analyses  of  Harrington  and  Kinnicutt  and  Soldner  give  con- 
trary results.— Editors.]  The  addition  of  salt,  however,  has 
some  advantages.  It  acts  as  a  stimulant  to  the  appetite  and 
increases  the  secretion  of  hydrochloric  acid,  thus  assisting  in 
digestion.  It  aids  in  the  solution  of  globulins  in  the  blood; 
this  group  of  proteids  being  insoluble  in  distilled  water,  but 
soluble  in  dilute  alkaline  solutions.  When  added  to  milk,  salt 
diminishes  its  coagulability  with  rennet  ferment  and  gastric 
juice,  and  may  therefore  be  of  advantage  in  feeding  infants 
with  weak  digestions. 

"It  is  a  curious  fact  that  all  carnivorous  animals  require 
no  additional  salt  with  their  food.  Herbivorous  animals  take 
a  considerable  quantity  of  it,  in  proportion  to  the  amount  of 
vegetable  food  ingested.  Vegetable  food  contains  much  potas- 
sium salt,  and  the  sodium  salt  is  required  to  neutralize  its 
effects.  It  is  important,  therefore,  to  add  salt  to  the  diet 
of  an  infant  who  is  given  vegetable  food  with  its  diet,  such 
as  barley-water,  etc.  There  is  one  cereal  which  contains  re- 
markably little  potassium, — namely,  rice. 

"  Iron. — Both  human  milk  and  cow's  milk  contain  a  very 
small  proportion  of  iron, — namely,  0.003  per  cent,  of  the  dried 
solids;  hence,  when  cow's  milk  is  diluted,  the  percentage  of 
iron  is  reduced  below  that  of  mother's  milk.  Deficiency  of 
iron  in  the  food  of  the  hand-fed  baby  may  produce  anaemia 
and  debility.  To  guard  against  this,  iron  must  be  given  by 
the  mouth,  and,  seeing  that  normally  it  is  taken  in  the  form 
of  organic  compounds,  it  is  better  to  administer  it  in  this 
form  rather  than  give  inorganic  preparations.  It  is  doubtful 
whether  iron  introduced  in  the  form  of  inorganic  salts  can 
be  converted  into  haemoglobin  by  synthesis.     Organic  ferru- 


WEIGHT   AND   GROWTH   OF  THE   INFANT.  255 

ginous  combinations  exist  in  the  yolk  of  an  egg  in  the  form 
of  nucleo-albumins,  analysis  showing  that  0.04  per  cent,  of 
the  dried  solids  of  the  egg-yolk  consist  of  iron. 

"  In  blood  and  raw  meat  juice  iron  is  contained  in  consider- 
able quantity  in  the  form  of  haemoglobin.  In  this  combina- 
tion the  iron  is  more  firmly  held  than  in  the  nucleo-albuminous 
compound  present  in  the  yolk  of  the  egg.  Nevertheless,  raw 
meat  juice  or  the  gravy  of  undercooked  meat  is  a  valuable 
addition  to  the  diet  of  an  infant  for  the  prevention  and  cure 
of  anaemia.  After  the  age  of  one  year  potatoes  (containing 
0.042  per  cent,  of  iron  in  the  dried  solids)  can  be  added  to 
the  diet.  About  0.02  per  cent,  of  iron  is  present  in  lean  meat, 
cereals,  and  leguminosae,  such  as  wheat  and  peas. 

"  Lime. — In  human  milk  0.0243  per  cent,  of  lime  is  present, 
in  cow's  milk  0.151  per  cent.,  and  in  the  yolk  of  egg  0.38  per 
cent.  Meat,  cereals,  and  leguminosae  contain  a  much  smaller 
proportion,  and  it  is  doubtful  whether  a  child  brought  up  on 
a  diet  devoid  of  milk  would  obtain  the  amount  of  lime  requi- 
site for  the  proper  development  of  its  bones.  It  is  uncertain 
whether  this  salt  can  be  absorbed  except  in  the  form  of  organic 
compounds,  and  it  is  exceedingly  improbable  that  it  is  ab- 
sorbed dissolved  in  water.  There  is  no  evidence  that  water 
rich  in  lime  salts  has  any  value  whatever  in  the  prevention  of 
rickets. 

"  Lime-water  in  saturated  solution  contains  less  lime  than 
cow's  milk;  consequently,  the  addition  of  this  fluid  to  milk 
can  exert  no  influence,  except  by  virtue  of  its  alkalinity.  Lime 
is  more  soluble  in  cold  than  in  hot  water,  so  that  when  lime- 
water  is  added  to  hot  milk,  some  of  the  salt  is  precipitated. 
The  lime  salts  in  milk  are  rendered  more  insoluble  by  pro- 
longed heating,  as  in  sterilization. 

"  Phosphorus  is  of  the  utmost  importance  in  the  formation 
of  bone  and  probably  in  the  prevention  of  rickets;  so  much 
so  that  in  recent  years  it  has  been  prescribed  for  rickets  and, 
according  to  some  authors,  with  considerable  success.     Six 


256  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

times  as  much  phosphorus  is  present  in  lean  beef,  yolk  of 
egg,  and  cow's  milk  as  is  found  in  mother's  milk.  Cereals, 
leguminOsas,  and  potatoes  contain  considerably  more  phos- 
phorus than  human  milk.  Lecithin  and  nuclein  are  bodies  con- 
taining phosphorus,  and  are  found  in  considerable  quantities  in 
nervous  tissues  and  ova.  It  is  not  known  whether  they  are  ab- 
sorbed and  digested,  but  the  administration  of  calves'  brains 
and  hard  roes  of  fish  is  certainly  harmless.  The  large  amount 
of  phosphorus  present  in  cow's  milk  indicates  that  ordinary 
dilutions  will  not  render  the  supply  of  this  salt  deficient.  If 
it  is  thought  that  more  is  required,  it  is  much  simpler  to 
administer  the  salt  in  the  form  of  the  yolk  of  egg  than  in 
the  form  of  inorganic  compounds,  and  in  all  probability  this 
is  better  digested  and  assimilated." 

In  order  to  compare  the  constituents  of  an  average  adult 
diet  and  that  for  an  infant  of  six  months,  weighing  6.7  kilo- 
grammes, we  have  taken  the  average  of  the  figures  given  in  the 
estimations  of  von  Kanke,  Moleschott,  Pettenkofer  and  Voit, 
and  Waller  (cited  by  Cautley),  and  those  for  an  infant's  diet 
as  estimated  by  Cautley,  allowing  that  a  healthy  infant  aged 
six  months  takes  a  litre  of  milk  daily,  and  calculating  from 
Leeds's  average  analysis  of  human  milk. 


Proteids    

Fat 

Carbohydrates 

Salts 

Water 2629 


"  On  comparing  the  latter  with  the  adult  diet  it  is  seen  that 
the  infant  requires  a  much  more  liberal  supply  of  each  of 
the   constituents   of  the   ordinary   diet   in   proportion   to   its 


Constituents  of  an 

average  adult 

diet. 

Diet  of  an  infant  aged 

six  months.     Weight, 

6.7  kilogrammes. 

Grammes. 

Grammes. 

121 

20 

94 

40 

350 

70 

26 

2 

WEIGHT   AND   GROWTH   OF   THE   INFANT.  257 

weight,  and  a  much  more  liberal  supply  of  fat  and  water  com- 
pared with  its  need  for  proteids.  Halliburton  estimates  the 
needs  of  an  infant  under  a  year  and  a  half  old  as  from  twenty 
to  thirty-six  grammes  of  proteids,  thirty  to  forty-five  grammes 
of  fat,  and  sixty  to  ninety  grammes  of  carbohydrates.  At 
present  it  is  impossible  to  give  more  definite  figures,  and  it 
must  be  remembered  that  the  requirements  of  the  individual 
child  may  vary  to  some  extent  from  the  average.  In  regard 
to  proteids,  Waller  has  pointed  out  that  in  proportion  to  body 
weight  the  amount  required  by  the  infant  is  greater  than  that 
required  by  the  adult,  but  that  in  proportion  to  the  body  sur- 
face the  amount  is  approximately  the  same.  Body  surface  is 
therefore  a  better  proportional  indication  than  body  weight." 

Kichmond.121  Milk  is  of  value  as  a  food  both  to  repair 
tissue  waste  and  as  a  source  of  energy.  Of  its  three  main 
constituents : 


Carbon. 
Percent. 

Fat  contains 75.63 

Sugar  contains 42. 11 

Proteids  contain 52.66 


Hydrogen. 
Per  cent. 

Nitrogen . 
Per  cent. 

Oxygen. 
Percent. 

11.87 

12.50 

6.43 

51.46 

7.13 

15.77 

22.77 

Fat  is  richest  in  carbon  and  hydrogen,  proteids  come  next, 
while  sugar  occupies  the  lowest  place.  Neither  fat  nor  sugar 
can  replace  the  proteids,  as  these  furnish  the  only  source  of 
nitrogen.  It  is  evident  that,  to  build  up  tissues  containing 
high  percentages  of  carbon  and  hydrogen,  fat  is  a  far  more 
advantageous  food  than  sugar.  The  value  of  milk  as  a  food 
for  infants  depends  largely  on  the  fat  present,  and  it  is  doubt- 
ful whether  fat  can  be  replaced  by  sugar  without  detriment 
to  anabolic  processes. 

Strohmer  has  given  the  following  table  of  the  values  for 
combustion  of  the  constituents  of  milk : 

17 


258  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

(  Butter  furnishes  9231.3  calories  per  kilogramme 

(  Other  fats    furnish     9500     calories  per  kilogramme 
f  Lactose        furnishes  3950     calories  per  kilogramme 
(_  Cane-sugar  furnishes  3955     calories  per  kilogramme 
?       .,         (  Casein  furnishes  5858.3  calories  per  kilogramme 

{  Albumin     furnishes  5735.2  calories  per  kilogramme 

These  values  assume  that  complete  combustion  takes  place. 
This  may  be  said  to  be  true  for  fat  and  sugar;  when  we 
consider  the  proteids,  we  must  remember  that  the  nitrogen 
is  not  excreted  as  such,  but  as  compounds,  of  which  urea  may 
be  taken  as  a  type.  The  heat  of  combustion  of  the  urea  from 
one  gramme  of  proteids  amounts  in  round  figures  to  fifteen 
per  cent,  of  the  total  heat  of  combustion.  It  is  necessary, 
therefore,  to  deduct  fifteen  per  cent,  of  the  heat  of  combus- 
tion of  proteids  in  calculating  isodynamic  metabolic  ratios. 

In  round  figures  the  following  will  be  the  calories  per  kilo- 
gramme developed  in  combustion  of  the  three  constituents 
in  the  human  body:   fat  9230,  sugar  3950,  proteids  4970. 

The  author  proposes  to  calculate  the  ratio  between  the 
various  constituents  as  follows: 

Anabolic  ratio   =  fat :  sugar  :  proteids  ;  or,  2.38  :  1  :  1.26 

Metabolic  ratio  =  fat  X  2.38  +  sugar  +  proteids  X  1-26 
proteids 

Instead  of  the  above  figures,  the  round  figures  2.5  and  1.25 
may  be  used  without  appreciable  error. 

The  ratios  of  mother's  milk  are  :  Anabolic  ratio   =    2.2:4.5:1 
Metabolic  ratio  =  11.3 

The  ratios  of  cow's  milk  are  :        Anabolic  ratio   =  1.15  :  1.4  :  1 

Metabolic  ratio  =  5.54 

In  calculating  these  ratios  it  is  assumed  that  the  constituents 
are  all  digestible.    The  marked  difference  is  due  to  the  smaller 


WEIGHT   AND   GROWTH   OF   THE   INFANT.  259 

amount  of  proteids  in  human  milk.  Experiments  have  shown 
that  children  do  not  derive  the  most  benefit  from  milk  unless 
the  anabolic  ratio  approximates  2:4:1  and  the  constituents 
are  of  such  a  form  that  they  are  as  finely  divided  as  possible 
in  the  stomach. 

The  condition  of  the  proteids  necessary  to  produce  a  fine 
state  of  division  in  the  stomach  is  attained  by : 

I.  Simple  dilution  with  water  and  the  addition  of  fat  and 
sugar. 

II.  Eemoval  of  casein  and  the  addition  of  fat  and  sugar. 

III.  By  acting  on  milk  with  a  proteolytic  enzyme — i.e., 
peptonizing  it — and  the  addition  of  fat  and  sugar. 

IV.  By  adding  a  preparation  of  diastase  and  diluting  it 
and  the  addition  of  fat  and  sugar. 

Marfan.105  Metabolism  experiments  have  proved  conclu- 
sively that  the  healthy  adult  organism  needs  for  its  proper 
development  and  growth  the  five  principal  food  elements,  all 
of  which  are  contained  in  milk, — namely,  fat,  proteids,  sugar, 
water,  and  mineral  salts.  Nothing  can  take  the  place  of  the 
proteids,  salts,  and  water.  To  a  certain  extent,  fat  and  sugar 
may  be  substituted  for  each  other,  but  any  attempt  at  abso- 
lute replacement  of  the  one  by  the  other  is  sure  to  lead  to 
digestive  disturbances.  Water  serves  as  a  substratum  for  nearly 
all  of  the  chemical  changes  of  the  human  body.  It  helps  to 
eliminate  the  products  of  metabolism,  it  keeps  the  alveolar 
surfaces  moist,  thus  favoring  the  diffusion  of  gases  in  the 
lungs,  and  it  plays  a  considerable  role  in  favoring  evaporation 
from  the  surface  of  the  body.  It  is  thus  a  factor  in  the  regu- 
lation of  the  animal  heat.  Forster  found  that  animals  fed 
on  foods  containing  no  mineral  salts  wasted  and  died  in  a 
short  period. 

The  principal  physiological  characteristic  of  infancy  is  that 
during  this  period  growth  is  more  rapid  than  at  any  subse- 
quent period  of  life,  and  is  the  more  rapid  the  younger  the 
child.    For  example,  the  child  doubles  its  weight  in  five  months 


260  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

and  triples  it  in  fifteen  months;  consequently,  assimilation 
predominates  largely  over  disassimilation.  To  establish  the 
balance  of  nutrition  in  the  first  period  of  infancy  we  must 
note:  first,  the  quantity  of  food  to  be  taken;  second,  the 
increase  in  weight;  third,  the  number  of  calories  consumed 
by  the  infant  organism;  fourth,  the  amount  of  urea,  water, 
and  carbon  dioxide  excreted.  Unfortunately,  on  the  last  two 
points  our  knowledge  is  still  imperfect.  For  example,  a 
breast-fed  infant  in  good  health,  weighing  on  the  average  five 
kilogrammes,  will  take  in  twenty-four  hours  about  eight  hun- 
dred grammes  of  milk,  and  will  gain  from  twenty-five  to 
thirty  grammes  a  day.  The  breast-milk  which  he  takes  con- 
tains in  each  one  thousand  grammes  fifteen  parts  of  casein, 
forty  parts  of  fat,  and  sixty-three  parts  of  sugar.  The  adult 
ingests  daily  for  each  kilogramme  of  his  body  weight  one  and 
seven-tenths  grammes  of  albumin,  0.85  gramme  of  fat,  and 
seven  and  a  half  grammes  of  carbohydrates.  The  infant  in- 
gests per  kilogramme  twice  as  much  albumin  and  five  times 
as  much  fat  as  the  adult  (the  quantity  of  milk-sugar  being 
estimated  as  fat  by  multiplying  by  the  ratio  ten  to  twenty- 
four).  Assimilation  is  thus  very  active  in  the  first  period 
of  life.  The  ratio  of  the  nitrogenous  to  the  non-nitrog- 
enous elements  in  the  diet  is  as  one  to  five  in  the  adult's 
food,  one  to  six  in  woman's  milk,  and  one  to  three  in  cow's 
milk. 

According  to  Lambling  (Le  Nord  Medical,  January  1,  1898), 
an  infant  consumes  up  to  the  age  of  two  years  one  hundred 
calories  per  kilogramme  per  day.  This  is  double  the  number 
of  calories  which  would  suffice  for  an  adult  engaged  in  moder- 
ate work.  Eubner  thinks  that  the  greater  extent  of  the  body 
surface  in  infants  as  compared  with  their  weight  causes  them 
to  lose  much  larger  amounts  of  heat  during  the  same  periods 
of  time.  Lambling  has  observed  that  if  we  compare  the  num- 
ber of  calories  consumed,  not  to  the  unit  of  weight  but  to  the 
unit  of  surface,  we  find  that  the  experiments  give  the  same 


WEIGHT   AND   GROWTH   OF   THE   INFANT.  261 

results  for  the  infant  as  for  the  adult.  He  has  estimated  the 
proportion  of  heat  furnished  by  the  different  elements  of 
milk.  In  one  hundred  calories  furnished  to  the  organism, 
the  following  is  the  ratio  of  the  different  elements  in  the 
food  : 


Adults.  Infants. 

Proteids '. 19  18 

Fat 30  53 

Carbohydrates 51  29 


During  the  first  year  the  infant  consumes  one  hundred 
calories  per  day;  from  two  to  five  years,  eighty  to  ninety; 
from  five  to  twelve  years,  sixty  to  eighty.  The  adult  consumes 
proportionately  more  carbohydrates  than  the  infant,  the  latter 
almost  double  the  quantity  of  fat  consumed  by  the  adult. 
This  preponderance  of  fatty  substances  is  to  check  albuminous 
waste  in  the  tissues  of  the  body;  part  of  the  fat  must  be  re- 
tained to  build  up  the  growing  structures.  After  weaning, 
when  the  milk  is  no  longer  the  sole  diet,  the  combustion  of  fat 
is  replaced  more  and  more  by  combustion  of  carbohydrates. 
The  carbohydrates  increase  until  they  preponderate  as  in  the 
adult. 

After  the  first  year  development  is  less  rapid,  and  the  supply 
of  albumin  and  fat  diminishes,  while  that  of  the  carbohydrates 
increases  until  it  is  finally  almost  double  that  of  the  fat 
and  albumin  together.  At  the  same  time  metabolism  is 
still  very  active.  From  one  to  two  years  the  infant  absorbs 
per  kilogramme  twice  as  much  albumin  as  the  adult,  three 
times  as  much  fat,  and  one  and  a  half  times  as  much  carbo- 
hydrates. 

The  alimentary  needs  of  infants  at  different  ages  have  been 
calculated  by  Marfan  as  follows,  on  the  basis  of  the  researches 
of  Camerer,  Forster,  Uffelmann,  Voit,  and  Riedel. 


Per  kilogramme. 

Albumin. 
Grammes. 

Fat. 

Grammes. 

Carbohydrates. 
Grammes. 

2.4 

2.8 

2.9 

3.7 

4.3 

4.4 

4.8 

5.6 

5.7 

4.5 

5.2 

5.4 

3.8 

4.5 

4.6 

4.4 

4.0 

8.9 

3.6 

2.7 

15.0 

262  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 


Age.  Weight. 

Kilos. 

Three  days 3.00 

Six  days 3.2 

Three  weeks 3.5 

Seven  to  ten  weeks 4.00 

Four  months 6.00 

One  and  a  half  years 9.00 

Two  and  a  half  years 10.00 

With  regard  to  the  need  of  salts  for  the  infant's  nutrition, 
we  note  that  the  child  fed  on  milk  obtains  per  kilogramme 
of  body  weight  a  greater  proportion  of  mineral  salts  than  the 
adult  on  an  ordinary  diet.  The  organism  at  first  needs  a 
considerable  quantity  of  inorganic  salts  to  build  up  the  grow- 
ing tissues,  whereas  the  adult  body  can  keep  itself  in  equilib- 
rium on  a  smaller  quantity. 

During  the  first  year  the  infant  takes  on  the  average  four 
grammes  of  albumin  per  kilogramme  of  body  weight, — i.e., 
twice  as  much  as  the  adult.  Up  to  five  or  six  months  urinaly- 
ses show  that  the  infant  eliminates  less  urea  per  kilogramme 
than  the  adult  in  nutritive  equilibrium  (see  J.  Kenault,  Trait  e 
des  Maladies  de  VEnfance,  vol.  iii.  p.  259).  Towards  fifteen 
months  the  infant  eliminates  more  urea  than  the  adult,  and 
the  quantity  increases  up  to  ten  years,  to  fall  subsequently 
and  reach  the  ratio  of  adult  life;  proportionately  the  infant 
ingests  more  nitrogenous  material  than  he  eliminates  (Carron 
de  la  Carriere  et  Monf et,  "  The  Normal  Urine  of  the  Infant 
after  Fifteen  Months,"  Academie  de  Medecine,  July  20, 
1897).  These  facts  are  in  accord  with  the  results  obtained 
by  weighing.  During  the  first  six  months  growth  is  more 
rapid  and  more  nitrogen  is  retained  than  during  the  second 
six  months  of  the  first  year. 

The  researches  of  Voit  and  Pettenkofer,  Forster,  and  more 


WEIGHT   AND   GROWTH   OF  THE   INFANT.  263 

recent  ones  by  Mensi,  of  Turin,  are  in  accord  in  showing  that 
the  infant  organism  from  birth  to  ten  years  eliminates  from 
one  and  a  half  to  two  and  a  half  parts  more  carbon  dioxide 
than  the  adult  organism.  This  excessive  carbonaceous  waste 
perhaps  occurs  at  the  expense  of  fat,  thus  serving  to  economize 
the  albumin  needed  for  growth.  Munk,  however,  attributes 
it  in  part  to  the  decomposition  of  albuminoids.  He  bases  this 
statement  on  the  fact  that  in  infants  carbon  dioxide  elimina- 
tion is  parallel  to  that  of  urea  (Munk  and  Ewald's  Treatise 
on  Dietetics). 

Phosphorus  and  Nitrogen  Metabolism. 

Arthur  Keller.185  Two  observations  were  undertaken  to 
determine  the  amount  of  nitrogen  excreted  in  the  intestinal 
secretions  and  epithelia.  In  each  case  the  infant  was  kept  for 
two  days  on  a  starvation  diet  of  sugar  and  water.  The  results 
gave  1.007.2  and  1.4618  grammes  dried  faeces  respectively,  with 
0.0716  and  0.0966  gramme  nitrogen.  While  these  figures  are 
of  course  not  of  general  application,  they  show  at  least  that 
the  amount  of  nitrogen  so  excreted  is  not  inconsiderable  as 
compared  with  the   small  total   content  of  nitrogen  in  the 


The  absorption  of  nitrogen  may  be  said  to  be  in  general 
better  on  a  diet  of  cow's  milk  than  on  one  of  breast-milk. 
Among  breast-fed  children  the  healthiest  show  the  highest 
figures.  Shortening  of  the  pauses  between  feedings  was  with- 
out influence  on  the  amount  of  nitrogenous  absorption,  as  was 
also  the  addition  of  sodium  phosphate  to  the  diet. 

The  absolute  amount  of  nitrogen  retention  depends  to  a  cer- 
tain degree  on  the  amount  of  nitrogen  in  the  food,  but  depends 
also  on  the  kind  of  food.  When  we  consider  the  percentage 
figures  of  retention,  we  find  that  a  greater  proportion  of  the 
food  nitrogen  is  retained  on  a  diet  of  mother's  milk  than  on  one 
of  cow's  milk.  Sick  children  utilize  the  nitrogen  of  mother's 
milk  just  as  well  as  healthy  ones ;  on  the  other  hand,  the  state 


264  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

of  the  child's  health  affects  quite  markedly  its  power  to  assimi- 
late the  nitrogen  of  cow's  milk.  It  is  also  remarkable  that  when 
sodium  phosphate  is  added  to  the  food,  the  utilization  of  nitro- 
gen is  better  than  in  all  other  cases. 

From  the  tables  cited  by  the  author  it  appears  that  two  in- 
fluences are  of  moment  for  the  utilization  of  nitrogen  by  the 
infant  organism:  the  kind  of  food  and  the  condition  of  the 
child's  health.  Other  factors  (even  the  amount  of  food),  unless 
marked  differences  exist,  possess  less  importance. 

Animal  experiments,  investigations  on  the  adult,  and  metab- 
olism experiments  on  the  infant  justify  the  conclusion  that 
the  differences  in  nitrogen  metabolism  are  due,  not  so  much  to 
the  different  constitution  of  the  albuminous  bodies  in  the  two 
kinds  of  milk  as  to  the  variations  in  milk-sugar  and  fat  con- 
tent. 

The  results  and  conclusions  to  be  drawn  from  tables  repre- 
senting the  sum  of  metabolism  experiments  of  different  ob- 
servers on  different  infants  fed  on  different  kinds  of  food  at 
different  times  of  life  and  under  varying  surroundings  are 
to  be  accepted  with  reserve.  They  become  of  more  value  when 
we  can  control  them  by  experiments  carried  out  on  the  same 
child.  Keller  found  that  in  the  case  of  a  child  fed  first  on 
breast-milk  and  then  on  cow's  milk,  in  the  latter  period  less 
nitrogen  was  absorbed  but  more  was  assimilated  than  in  the 
former.  This  observation  applies  as  well  to  the  healthy  as 
to  the  sick  child. 

The  addition  of  carbohydrates  to  cow's  milk,  in  the  form 
of  maltose  or  milk-sugar,  diminishes  the  absorption  but  at 
the  same  time  heightens  the  retention  of  nitrogen.  In  cor- 
respondence with  these  results,  it  is  probably  true  that  the 
higher  percentage  of  milk-sugar  in  mother's  milk  shares  in 
bringing  about  the  greater  retention  of  its  nitrogen. 

Of  the  nitrogen  in  the  starch,  a  decidedly  smaller  part  is 
absorbed  (at  any  rate,  in  the  case  of  infants)  than  of  the 
nitrogen  in  mother's  milk. 


WEIGHT   AND   GROWTH   OF   THE   INFANT.  265 

When  malt  soup  is  given,  in  which  one-fourth  of  the  nitrogen 
comes  from  the  starch,  only  a  smaller  proportion  of  the  nitro- 
gen administered  will  be  absorbed,  but,  notwithstanding,  more 
nitrogen  will  be  assimilated  than  if  we  gave  the  same  amount 
in  the  form  of  cow's  milk. 

Up  to  the  present  we  have  no  knowledge  of  the  influence  of 
the  fat  content  on  the  assimilation  of  nitrogen. 

The  addition  of  salts  to  the  food  increases  the  retention 
of  nitrogen,  whereas  the  addition  of  hydrochloric  acid  (Raud- 
nitz)  does  not  affect  it. 

Phosphorus  Metabolism. 

Keller  finds  that  the  quantity  of  phosphorus  administered 
in  the  food  is  no  criterion  for  the  amount  of  absorption  and 
retention  of  phosphorus,  but  that  other  influences,  such  as 
the  kind  of  food  and  the  state  of  the  child's  health,  are  of 
more  moment. 

In  the  case  of  normal  healthy  infants  these  experiments 
prove  quite  conclusively  that  the  organic  phosphorus  combina- 
tions of  woman's  milk,  as  well  as  those  of  cow's  milk,  become 
soluble  in  the  digestive  fluids.  The  amount  of  phosphorus 
present  in  the  faeces  of  healthy  breast-fed  children  is  very 
small;  besides  this,  a  considerable  part  of  this  phosphorus 
comes  from  the  digestive  juices  and  the  intestinal  epithelium. 
The  experiments  show  that  the  phosphorus  in  woman's  milk 
can  be  absorbed  almost  completely  by  the  healthy  child.  The 
same  can  be  said  for  the  phosphorus  in  cow's  milk.  The 
experiments  also  show  that  absorption  is  somewhat  more  com- 
plete in  the  case  of  the  artificially  fed  child,  but  retention 
of  the  food  phosphorus  decidedly  less  than  in  the  case  of 
the  child  at  the  breast.  The  differences  in  phosphorus  metab- 
olism are  more  conspicuous  in  the  case  of  sick  children,  and 
here  the  advantage  is  again  with  the  nursing  child.  If  we 
are  forced  to  nourish  such  a  child  artificially,  favorable  con- 
ditions for  phosphorus  retention  are  furnished  by  a  food  which 


266  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

contains  a  plentiful  amount  of  phosphates,  besides  phosphorus 
in  organic  combination. 

Keller  reviews  the  metabolism  work  of  Bendix,  Lange  and 
Berend,  and  some  of  his  own  experiments,  and  concludes  that 
the  results  are  contradictory  and  unsatisfactory.  There  is 
not  enough  in  them  to  be  made  the  basis  of  any  definite  con- 
clusions. Clinical  observation  is  at  present  the  only  reliable 
guide,  and  it  speaks  against  excessive  administration  of  pro- 
teids. 

The  metabolism  experiments  of  Eubner  and  Heubner  com- 
prise three  cases,  all  of  which  were  studied  with  the  greatest 
care.  A  full  account  of  them  can  be  found  in  the  Zeitschrift 
fur  Biologie.  While  such  experiments  are  of  great  interest, 
and  may  in  the  course  of  time  reach  a  sufficient  number  to 
be  of  value  to  the  practitioner  in  giving  him  a  basis  on  which 
he  may  be  able  to  calculate  the  needs  of  the  organism  in  food- 
stuffs, as  they  are  at  present  carried  out,  metabolism  experi- 
ments on  the  infant  do  not  approximate  sufficiently  to  the 
normal  conditions  to  be  considered  final,  and  we  must  be  very 
cautious  in  drawing  far-reaching  conclusions  from  the  results 
of  a  few  isolated  cases  under  varying  conditions  as  to  the 
child's  age,  diet,  environment,  etc. 

Blauberg  193  investigated  the  mineral  salt  metabolism  in 
two  cases,  both  healthy,  one  breast-fed  and  the  other  taking 
pure  cow's  milk;  also  the  mineral  metabolism  in  an  atrophic 
infant.  "  Up  to  a  certain  degree  the  conclusion  seems  justified 
that  too  great  a  dilution  of  cow's  milk  has  an  unfavorable 
influence  on  the  absorption  of  the  mineral  salts  of  the  same. 
...  In  general,  we  may  safely  say  that  the  salts  of  woman's 
milk  are  much  better  absorbed  by  the  infant  than  those  of 
cow's  milk." 

Monti."  A  milk  mixture  prepared  according  to  Heub- 
ner's  method,  consisting  of  equal  parts  of  milk  and  water  and 
enough  milk-sugar  to  bring  the  strength  of  the  solution  up 
to  six  per  cent,  sugar,  will  contain  the  following  values  of 


WEIGHT   AND   GROWTH    OF   THE   INFANT. 


267 


albumin,  fat,  and  sugar,  proportionately  to  the  amount  of 
food  taken. 


«  No.  of  cc. 

g  •  per  meal. 

One  week 30.0 

Two  weeks 45.0 

Three  weeks 45.0 

Four  weeks 60.0 

Five  weeks 75.0 

Six  weeks 90.0 

Seven  weeks 105.0 

Eight  weeks 120.0 

Nine  weeks 135.0 

Ten  weeks 150.0 

Eleven  weeks 165.0 

Twelve  weeks 180.0 

Thirteen  weeks 190.0 

Fourteen  weeks 200.0 


O.  OI 

leals. 

Total  uany 
amount. 

Proteids. 

Fat. 

Sugar. 

Cc. 

Per  cent. 

Per  cent. 

Per  cent. 

8 

240.0 

4.08 

4.39 

14.06 

8 

360.0 

6.12 

6.58 

21.09 

7 

315.0 

5.27 

5.67 

18.16 

7 

420.0 

7.14 

7.68 

24.61 

7 

525.0 

8.84 

9.36 

30.16 

7 

630.0 

10.71 

11.52 

36.54 

7 

735.0 

12.41 

13.14 

42.34 

7 

840.0 

14.28 

15.12 

48.72 

7 

945.0 

15.98 

16.92 

54.52 

7 

1050.0 

17.85 

18.90 

60.90 

6 

990.0 

16.83 

17.80 

57.42 

6 

1080.0 

18.30 

19.44 

62.64 

6 

1140.0 

19.38 

19.52 

66.12 

6 

1200.0 

20.40 

21.60 

67.60 

Biedert's  Cream  Mixture?* 


Weight  in  grammes  of 
different  constituents. 

Percentage  of 
different  con- 
stituents. 

Age. 

No.  of 
mix- 
ture. 

Cream. 

Water. 

Sugar 

of 
milk. 

Milk. 

Casein. 

Fat. 

Sugar. 

One  week 

1 
2 
3 

125 
125 
125 

375 
375 
375 

15 
15 
15 

60 
125 

1.0 
1.4 

1.8 

2.5 
2.7 
2.7 

40 

Two  weeks 

3  8 

Three  to  four  weeks . . . 

3.8 

Five  to  six  weeks 

3 

125 

375 

15 

125 

1.8 

2.7 

3.8 

Seven  to  eight  weeks . . 

4 

125 

375 

15 

250 

2.3 

2.9 

3.8 

Nine  to  ten  weeks 

5 

125 

375 

15 

375 

2.6 

3.0 

3.9 

Eleven  to  twelve  weeks 

6 

250 

10 

500 

3.2 

2.8 

4.0 

268 


THE   ARTIFICIAL   FEEDING   OF   INFANTS. 


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WEIGHT   AND   GROWTH   OF   THE   INFANT. 


269 


Monti.96     Pfeiffer  estimates  the  values  of  the  different 
constituents  of  mother's  milk  in  the  subjoined  table. 


Age. 


Total 
amount. 


Cc. 

One-half  week 104 

One  week 254 

Two  weeks 334 

Three  weeks 449 

Four  weeks 550 

Five  to  six  weeks 749 

Seven  to  eight  weeks 864 

Nine  to  ten  weeks 926 

Eleven  to  twelve  weeks 896 

Thirteen  to  fourteen  weeks 966 

Fifteen  to  sixteen  weeks 974 

Seventeen  to  eighteen  weeks 996 

Nineteen  to  twenty  weeks 996 

Twenty-one  to  twenty-four  weeks.  1023 

Twenty-five  to  twenty-eight  weeks  1051 

Twenty-nine  to  thirty-two  weeks  .  741 

Thirty-three  to  thirty-six  weeks  . .  482 


No.  and 
size  of 
meals. 

Proteids. 
Per  cent. 

Fat. 
Per  cent. 

Sugar. 
Percent. 

8x     13 

4.40 

2.81 

4.69 

7x    36 

8.74 

6.86 

11.44 

7x    48 

7.64 

12.13 

15.05 

7x    68 

10.27 

12.13 

20.23 

7x    71 

12.58 

17.86 

24.78 

7x107 

13.82 

22.52 

41.47 

7x123 

15.83 

26.40 

45.03 

7x132 

17.68 

20.43 

55.28 

7x128 

17.10 

20.25 

53.50 

7x138 

19.53 

39.02 

59.12 

7x139 

19.62 

39.23 

59.39 

7x142 

17.38 

52.36 

7x142 

17.42 

52.28 

6x167 

15.82 

26.88 

60.00 

6x174 

11.99 

34.77 

60.40 

6x123 

12.15 

28.69 

42.80 

6x    88 

7.26 

11.62 

28.94 

CHAPTEE   XL 
THE    FEEDING    OF    PREMATURE    INFANTS. 

In  the  Archives  of  Pediatrics,  No.  17,  1900,  James  D.  Voor- 
hees  216  has  emphasized  some  of  the  most  important  points  in 
the  care  of  premature  infants  from  his  experience  at  the 
Sloane  Maternity  Hospital. 

Temperature. — This  should  be  neither  too  low,  which  favors 
excessive  heat  radiation,  nor  too  high,  which  increases  cell 
metabolism.  From  86°  to  92°  F.  seems  to  be  the  correct 
average. 

Fresh  Air. — The  importance  of  this  can  be  appreciated 
when  we  realize  that  the  tissues  of  the  nose  and  throat  and 
mouth  of  the  premature  infant  are  extremely  sensitive  and 
unable  to  throw  off  infectious  material  conveyed  by  the  dust. 

The  infant  should  lie  on  a  very  soft  pillow.  Preliminary 
bathing  should  be  avoided.  If  wrapped  in  cotton,  this  should 
not  be  placed  directly  next  to  the  skin,  but  a  light  shirt  and 
diaper  should  be  first  employed.  The  infant  should  not  be 
disturbed  to  change  the  latter  oftener  than  absolutely  neces- 
sary. 

Feeding. — As  a  routine  practice,  within  six  hours  after 
birth  Voorhees  begins  by  administering  from  one-half  to  one 
drachm  of  a  five  to  six  per  cent,  lactose  solution  every  hour. 
In  from  twenty-four  to  thirty-six  hours  he  adds  equal  parts 
of  breast-milk,  preferably  obtained  from  a  wet-nurse  who  is 
from  seven  to  eight  days  post-partum.  The  amount  at  each 
feeding  is  increased  one  drachm  at  a  time  until  on  the  sev- 
enth day  the  baby  is  taking  from  six  to  eight  drachms  every 
hour. 

If  the  stools  are  normal,  the  proportion  of  milk  can  be  in- 
creased and  the  sugar  solution  decreased.  By  adding  a  little 
270 


THE   FEEDING   OF   PREMATURE   INFANTS.  271 

lime-water,  pure  breast-milk  can  often  be  used  at  two  weeks 
of  age.  The  infant  will  usually  nurse  through  a  small  nipple. 
In  some  cases  we  may  have  to  make  use  of  a  medicine-dropper, 
and  occasionally,  when  the  infant  is  very  weak  or  unable  to 
swallow,  gavage  is  necessary.  In  the  latter  case,  however, 
they  seldom  do  well,  as  regurgitation  is  almost  sure  to  occur. 
In  this  way  the  nasopharynx  is  filled,  and  on  the  next  inspira- 
tion some  of  the  fluid  is  drawn  into  the  larynx  and  even  into 
the  bronchi. 

When  the  diet  consists  of  pure  breast-milk,  the  intervals 
should  be  gradually  increased  to  two  hours,  so  that  by  the  time 
full  term  is  reached  the  amount  and  interval  will  correspond 
to  those  of  the  normal  infant. 

The  results  with  diluted  cow's  milk  are  not  nearly  so  satis- 
factory as  with  the  above  plan. 

Weight. — Premature  infants  lose  considerably  more  in  pro- 
portion to  their  birth  weight  than  babies  at  term,  and  regain 
their  original  weight  more  slowly.  Indeed,  if  this  has  been 
accomplished  by  the  end  of  the  second  or  third  week  they 
have  done  remarkably  well. 

In  regard  to  the  use  of  the  incubator,  the  general  rule  at 
the  Sloane  Maternity  Hospital  is  to  put  the  infant  in  cotton 
and  surround  it  with  hot-water  bottles  when  its  weight  is  near 
five  pounds.  If  it  does  not  thrive,  or  if  the  temperature  falls, 
the  incubator  must  be  used.  Those  weighing  four  and  a  half 
pounds  or  less  are  put  at  once  into  the  "  couveuse." 

According  to  the  statistics  of  Tarnier,  Charles,  and  the 
Sloane  Maternity  Hospital: 

At  six  months  of  age  from  10-16  per  cent,  are  saved 

At  six  and  a  half  months  of  age     from  20-30  per  cent,  are  saved 
At  seven  months  of  age  from  40-49  per  cent,  are  saved 

At  seven  and  a  half  months  of  age  from  75-77  per  cent,  are  saved 
At  eight  months  of  age  from  70-88  per  cent,  are  saved 

Vanderpoel  Adriance.184  The  importance  of  proper  feed- 
ing in  cases  of  prematurity  cannot  be  overestimated.     In  the 


272  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

first  place,  the  gastro-intestinal  tract  is  so  poorly  developed 
that  fats  and  proteids  are  feebly  digested.  If  modified  milk 
is  administered,  it  must  be  weak,  not  containing  more  than 
one  per  cent,  of  fat  and  0.50  per  cent,  of  proteids,  until  the 
alimentary  tract  is  educated  to  its  task.  Modified  milk  is 
warmly  recommended  by  Rotch,  of  Boston,  but  our  experience 
indicates  that  it  should  not  be  used  when  proper  breast-milk  is 
available. 

Mother's  milk  is  the  ideal  food,  and  every  premature  infant 
should  have  it  if  its  variations  and  management  are  properly 
understood.  The  excess  of  proteids  in  colostrum  milk  is  due 
to  the  sudden  assumption  of  the  mammary  function.  The 
breasts  are  unexpectedly  engorged  with  an  increased  blood- 
supply  and  the  mammary  cells  forced  to  activity.  It  is  no 
marvel  that  during  this  strain  the  secreting  cells  permit  of  a 
serous  transudation  and  that  an  excess  of  albumin  is  found 
in  the  secretion. 

The  milk  offered  by  the  breasts  during  the  first  days  after  a 
premature  labor  is  colostrum  milk,  and  has  its  characteristics, 
but  to  an  exaggerated  degree.  The  marked  increase  in  the 
amount  of  proteids  is  especially  noticeable.  The  excess  con- 
tinues longer,  and  it  is  not  easily  dispelled.  It  has  even  been 
found  persisting  as  high  as  two  per  cent,  in  the  second  month. 
Analyses  of  Premature  Milk  at  Successive  Times. 

_        .  a  .  One  month  and 

Four  days.        Seventeen  days.  ten  da 

Per  cent.  Per  cent.  Per  cent. 

Fat 3.39  3.32  3.33 

Carbohydrates 5.02  4.43  6.64 

Proteids 4.90  3.88  1.71 

Salts  0.31  0.26  0.10 

Total  solids 13.66  11.91  11.79 

Water 86.32  88.08  88.20 

These  analyses  demonstrate  an  excessively  high  proteid  per- 
centage, accompanied  by  a  correspondingly  high  percentage  of 


THE   FEEDING   OF   PREMATURE   INFANTS.  273 

salts.  The  amount  of  carbohydrates  is  lower  than  in  any  other 
series  of  milk  analyzed.  The  management  of  this  condition 
is  difficult,  since  the  milk  of  prematurity  persistently  main- 
tains this  high  percentage  of  proteids.  It  may  be  reduced  by 
giving  large  quantities  of  water  to  the  mother  or  by  pumping 
the  milk  and  diluting  it  with  sugar  of  milk  solution.  Even  if 
our  efforts  are  successful,  however,  the  milk  presents  different 
characteristics  from  that  later  in  lactation  and  cannot  be 
administered  with  safety. 

In  cases  of  prematurity,  then,  a  wet-nurse  should  be  secured. 
Her  infant  must  be  healthy,  full  term,  and  two  weeks  of  age 
(better,  a  month),  in  order  that  the  characters  of  the  colostrum 
period  may  be  lost,  and  nothing  will  better  determine  the 
quality  of  her  milk  than  its  chemical  examination.  Meanwhile 
the  secretion  of  the  mother  should  be  maintained  by  pumping 
and  massage,  so  that  it  can  be  resorted  to  at  the  proper  time. 

Cautley.38  Hecker  and  Lusk  give  the  following  table, 
showing  the  weight  of  premature  infants  and  the  normal  daily 
increase. 

At  twenty-four  weeks  they  should  weigh  690  grammes;  at 
twenty-eight  weeks,  1170  grammes;  at  thirty-two  weeks,  1560 
grammes;  at  thirty-six  weeks,  1920  grammes;  at  thirty-eight 
weeks,  2310  grammes.  During  this  time  they  should  gain 
daily  from  0.75  to  one  per  cent,  of  their  weight. 

Potel,  from  the  investigation  of  three  hundred  and  fifty 
cases,  gives  the  following  estimates: 

Age.  Weight.  Average^  gain  in 

Grammes.  Grammes. 

Six  and  a  half  months 1400  9.4 

Seven  months 1700  11.5 

Seven  and  a  half  months 1900  13.8 

Eight  months 2150  22.8 

Of  these  three  hundred  and  fifty  cases  nearly  fifty  per  cent, 
survived.     The  gastric  capacity  may  be  roughly  estimated  at 

18 


274  THE  ARTIFICIAL   FEEDING   OF  INFANTS. 

one  per  cent,  of  the  body  weight.  In  modifying  milk  to  suit 
these  cases  we  use  the  same  constituents,  simply  reducing  the 
percentage  of  solids. 

Kotch  gives  the  following  formulas :  Formula  I.  At  from 
twenty-eight  to  thirty-six  weeks,  proteids  0.5  per  cent.,  fat 
one  per  cent.,  sugar  three  per  cent.  If  the  infant  is  not  satis- 
fied, or  if  the  child  is  unusually  large,  or  when  it  is  thirty 
weeks  old,  we  may  give  Formula  II. :  proteids  0.5  per  cent., 
fat  1.5  per  cent.,  sugar  four  per  cent.  If  the  infant  is  over 
thirty-two  weeks  old,  give  Formula  III. :  proteids  0.75  per 
cent.,  fat  1.5  per  cent.,  sugar  five  per  cent. 

Give  twenty-four  meals  a  day:  of  Formula  I.  four  cubic 
centimetres  each,  heated  to  75°  C. ;  of  Formula  II.  eight  cubic 
centimetres  each,  heated  to  75°  C. ;  of  Formula  III.  twelve 
cubic  centimetres  each,  heated  to  75°  C.  If  the  infant  is  over 
thirty-six  weeks  old,  give  Formula  IV. :  proteids  one  per  cent., 
fat  two  per  cent.,  sugar  5.5  per  cent.  Give  twenty-four  meals 
a  day,  of  sixteen  cubic  centimetres  each,  heated  to  75°  C. 

If  the  infant  cannot  digest  these  mixtures,  try  condensed 
milk  or  a  mixture  of  egg  albumin,  water,  cream,  and  sugar. 
Kaw  meat  juice  must  also  be  given.  It  is  better  to  feed  fre- 
quently and  in  small  quantities  than  to  risk  causing  dilatation 
of  the  stomach  and  gastro-enteric  disorders  by  giving  larger 
quantities  less  frequently. 

If  the  child  is  thriving,  we  can  gradually  increase  the  inter- 
vals until  at  term  it  takes  normal  amounts  at  normal  intervals. 
If  the  infant  is  too  weak  to  nurse,  special  apparatus  has  to  be 
employed  which  will  force  food  into  its  mouth,  or  gavage  must 
be  resorted  to. 

Ashby  and  Wright.2  It  is  probably  best  to  draw  off  the 
mother's  milk,  dilute  it,  and  feed  the  premature  infant  through 
a  pipette.  Failing  in  this,  sterilized  whey  may  be  used,  diluted 
with  water  if  necessary.  Give  from  two  to  four  drachms  every 
hour. 


CHAPTEK   XII. 
PRINCIPLES    OF   INFANT   FEEDING. 

When  we  survey  the  various  methods  which  have  been  ad- A 
vocated  in  different  parts  of  the  world  for  the  artificial  feeding 
of  infants,  we  encounter  wide  differences  of  opinion. 

In  England,  France,  Germany,  and  Austria  the  prevailing 
tendency  is  to  feed  the  infant  on  milk  mixtures  containing 
high  proteid  percentages.  Milk  diluted  one-third  or  equally 
with  water,  and  sweetened,  is  considered  the  proper  food  for 
a  healthy  babe  during  the  first  months  of  life;  this  diet  is 
continued  until  at  the  age  of  eight  or  nine  months  whole  milk 
is  given.  Although  there  is  a  rather  low  fat  percentage  in 
such  mixtures,  those  who  advocate  this  method  of  feeding 
do  not  consider  that  it  is  necessary  to  remedy  the  delicit  in 
fat  by  the  addition  of  cream ;  some  of  them  advise  the  addition 
of  an  excess  of  sugar  to  take  the  place  of  the  fat.  Sterilization  A 
of  the  milk  is  considered  practically  indispensable  by  most  / 
French  and  German  pediatrists.  / 

Attempts  have  been  made  by  Heubner  and  others  to  base  the 
food  requirements  of  the  infant  on  the  number  of  calories 
daily  consumed,  taking  as  a  basis  the  number  of  heat  units 
furnished  by  definite  quantities  of  mother's  milk  (the  compo- 
sition of  the  latter  being  assumed  to  be  fairly  constant).  But 
when  we  consider  how  markedly  the  needs  of  different  infants 
vary,  depending  on  their  rate  of  growth,  strength,  digestive 
capacity,  etc.,  it  seems  certainly  more  advisable  to  follow  broad 
practical  lines  in  the  regulation  of  their  diet  than  to  estimate 
their  food  requirements  according  to  strictly  scientific  prin-      \ 

ciples. 

275 


276  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

The  majority  of  leading  American  writers  and  teachers  em- 
phasize the  necessity  for  greater  dilution  of  cow's  milk  to  ren- 
der it  easy  of  assimilation  by  the  young  infant.  They  advise 
to  begin  the  administration  of  cow's  milk  by  diluting  it  three 
or  four  times  with  water,  gradually  increasing  the  strength 
of  the  milk  mixture  until  the  end  of  the  first  year  or  later, 
when  'whole  milk  can  usually  be  given  without  harm.  To 
compensate  for  the  low  percentage  of  fat  which  results  from 
high  dilution  of  milk,  the  addition  of  small  quantities  of  cream 
to  the  milk  mixture  is  advised,  while  the  percentage  of  sugar 
is  increased  by  the  addition  of  milk-sugar  until  it  equals 
six  or  seven  per  cent.,  the  proportion  present  in  mother's 
milk. 

When  the  process  of  sterilization  was  introduced,  American 
physicians  were  among  the  first  to  recognize  its  importance 
and  the  necessity  for  its  employment  under  certain  conditions 
and  at  certain  times  of  the  year,  to  render  milk  fit  for  the 
infant's  use.  They  were  equally  prompt  to  note  the  advantages 
of  pasteurization;  the  latter  method  of  heating  milk  soon 
came  into  general  use  in  America,  while  it  is  only  of  late  years 
that  much  notice  of  it  has  been  taken  by  Continental  authori- 
ties. 

Unquestionably  the  greatest  step  in  advance  in  recent  years 
towards  the  successful  hand  feeding  of  infants  has  been  the 
discovery  that  it  is  possible  to  produce  practically  pure  sterile 
milk,  and  thus  dispense  with  sterilization  altogether  in  pre- 
paring the  child's  food.  To  Henry  L.  Coit,  of  Newark,  belongs 
the  credit  of  having  demonstrated  the  fact  to  the  American  pro- 
fession and  to  the  public  at  large  that  pure  so-called  "  certified 
milk"  could  be  obtained  by  instituting  proper  hygienic  pre- 
cautions regulating  the  production  and  care  of  the  milk. 
"  Certified  milk"  can  now  be  obtained  in  quite  a  number  of 
our  large  cities.  Its  price  is  necessarily  higher  than  that  of 
ordinary  milk,  but  it  seems  probable  that,  when  the  public 
becomes  sufficiently  alive  to  the  importance  of  obtaining  clean 


PRINCIPLES   OF   INFANT   FEEDING.  277 

milk,  competition  will  reduce  its  cost  and  bring  it  within  the 
reach  of  all.  Sterilization  and  pasteurization  will  then  become 
of  minor  importance. 

As  Baginsky  has  well  said,  the  chief  requisite  for  success 
in  the  management  of  the  infant's  diet  is  the  ability  to  make  a 
thorough  study  of  the  needs  of  the  individual  case  and  to  treat 
the  child  accordingly.  Since  no  two  children  have  identical 
food  requirements,  the  physician  who  can  correctly  determine 
the  qualitative  composition  of  the  food — that  is,  the  relative 
proportion  of  the  different  ingredients  suited  to  the  particular 
case — will  be  more  successful  than  he  who  prescribes  a  definite 
quantity  of  a  food  which,  theoretically  or  on  scientific  grounds, 
the  infant  should  be  able  to  digest. 

For  the  convenience  of  the  reader  it  has  seemed  advisable 
to  classify  the  various  methods  advocated  for  the  feeding  of 
healthy  infants  before  discussing  in  detail  the  principles  in- 
volved. 

I.  Whole  Milk. — Some  pediatrists,  most  of  them  French, 
contend  that  whole  cow's  milk,  provided  it  has  been  sterilized, 
can  safely  be  administered  even  to  the  youngest  infant.  This 
view  has  not  found  general  favor  in  this  country.  It  is  con- 
trary to  the  great  mass  of  clinical  evidence,  which  has  taught 
us  that  the  majority  of  healthy  infants  cannot  properly  digest 
pure  cow's  milk  until  near  the  end  of  the  first  year.  Undoubt- 
edly there  are  numerous  exceptions  to  this  rule.  Czerny  and 
Schlesinger  have  called  attention  to  the  fact  that  in  some  cases 
of  malnutrition  from  improper  feeding  nothing  is  so  satisfac- 
tory as  the  administration  of  small  amounts  of  whole  milk  at 
long  intervals  (from  three  to  five  hours).  No  doubt  many 
of  these  cases  had  previously  been  fed  on  excessive  amounts 
of  highly  diluted  milk  mixtures  which  did  not  contain  enough 
nourishment  to  meet  the  demands  of  the  organism.  When 
excessive  quantities  of  water  are  given  in  this  way  for  long 
periods  of  time,  we  fail  to  supply  the  necessary  physiological 
stimulus  to  the  gastric  secretions,  we  interfere  with  digestion 


278  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

by  dilution  of  the  gastro-intestinal  juices,  and  we  run  serious 
risk  of  causing  dilatation  of  the  walls  of  the  already  enfeebled 
stomach.  We  must  therefore  not  lose  sight  of  the  fact  that 
in  a  certain  class  of  cases  it  may  be  expedient  to  resort  to  a 
diet  of  whole  milk  long  before  the  child,  from  the  theoretical 
stand-point,  could  be  expected  to  digest  it. 

II.  Moderate  Dilutions  (i.e.,  High  Proteids). — Many 
pediatrists  advise  plain  dilutions  of  milk  with  water  or  barley- 
water  with  sugar  added.  Heubner,  Marfan,  and  Koplik  are 
prominent  advocates  of  this  method  of  feeding,  which  is  based 
on  the  conviction  that  the  healthy  infant  can  digest,  even  at  an 
early  age,  a  mixture  containing  two  parts  of  milk  and  one  of 
the  diluent  (the  so-called  Heubner-Hoffmann  Mixture).  Aver- 
age milk  diluted  one-third  will  contain  about  two  and  a  half 
per  cent,  proteids  and  from  two  to  two  and  a  half  per  cent, 
fat.  Enough  lactose  should  be  added  to  make  the  proportion 
of  sugar  seven  per  cent.  Undoubtedly  many  infants  will  thrive 
on  this  mixture,  which  has  at  least  the  advantage  of  simplicity 
of  preparation  to  recommend  it.  When  we  consider,  though, 
the  frequency  with  which  cases  of  indigestion  and  malnutrition 
are  encountered  among  infants  who  have  been  fed  during  the 
first  months  of  life  on  milk  so  slightly  diluted,  we  must  recog- 
nize that  a  very  large  proportion,  even  of  healthy  infants,  can- 
not digest  and  assimilate  the  Heubner-Hoffmann  Mixture  at 
this  period.  The  high  proteid  content  of  this  mixture  con- 
stitutes the  chief  difficulty  for  the  digestion  of  the  young  in- 
fant; at  a  later  period  of  life  (six  months  and  over)  the  low 
fat  content  will  be  an  objection. 

III.  High  Dilutions  (i.e.,  Low  Proteids). — Biedert,  John 
Forsyth  Meigs,  and  Jacobi  were  the  first  to  uphold  the  doc- 
trine that  cow's  milk  should  be  diluted  for  the  young  infant 
three  or  four  times  with  water  until  the  proportion  of  proteids 
is  reduced  to  about  one  per  cent,  (milk  one  part,  water  three 
parts,  give  proteids  one  per  cent.,  fat  from  three-quarters  to 
one  per  cent.).    They  arrived  at  this  conclusion  as  the  result 


PRINCIPLES   OF   INFANT   FEEDING.  279 

of  their  clinical  observation  before  the  amount  of  casein  in 
mother's  milk  had  been  accurately  determined.  (The  idea  of 
adding  cream  to  the  milk  mixtures  to  supply  the  deficit  of 
fat  caused  by  dilution  seems  to  have  originated  with  Biedert 
abroad  and  with  the  elder  Meigs  in  this  country.)  Undoubt- 
edly the  administration  of  high  dilutions  of  milk  with  cream 
and  sugar  added  is  one  of  the  most  widely  applicable  and  most 
serviceable  methods  of  infant  feeding. 

IV.  Top-Milk  Mixtures. — Instead  of  adding  cream  to  di- 
lutions of  milk  and  water,  dilutions  of  top  milk  may  be  em- 
ployed. It  is  convenient  to  denominate  as  "top  milk"  the 
upper  layers  of  milk  which  has  stood  for  a  sufficient  length  of 
time  (from  twelve  to  twenty-four  hours)  to  allow  the  gravity 
cream  to  rise  to  the  surface. 

V.  Whey  Mixtures. — Monti,  of  Vienna,  is  the  principal 
advocate  of  the  use  of  whey  and  milk  mixtures  for  healthy 
infants.  Whey  may  be  added  to  either  milk  or  cream.  The 
advantages  of  such  mixtures  are  obvious.  We  can  give  almost 
any  desired  proportion  of  casein  and  fat  together  with  the 
easily  digested  whey-proteids.  Such  mixtures  are  especially 
adapted  for  difficult  cases  in  which  the  digestion  of  casein  is 
at  fault. 

VI.  Laboratory  Milk. — The  introduction  of  the  Milk- 
Laboratory  is  the  work  of  T.  M.  Rotch,  of  Boston,  and  repre- 
sents one  of  the  latest  advances  in  the  scientific  feeding  of 
infants.  The  great  advantage  of  Laboratory  Milk  is  that  we 
can  be  sure  of  the  exact  composition  of  the  milk  food  we  are 
giving.  We  are  able  to  call  in  our  prescriptions  for  any  de- 
sired percentage  of  the  different  ingredients  and  can  practi- 
cally eliminate  the  danger  of  the  milk  becoming  contaminated 
before  it  roaches  the  consumer. 

One  objection  has  been  raised  against  Laboratory  Milk  pre- 
pared with  centrifugal  cream, — namely,  that  the  natural  con- 
dition of  the  elements  of  the  milk  is  replaced  by  an  artificial 
combination  of  these  elements;    to  accomplish  this,  the  milk 


280  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

is  first  separated  into  a  solution  of  proteids  (fat-free)  and  a 
solution  of  cream  with  low  proteids,  and  then  recombined. 
It  is  an  open  question  whether  the  physical  and  chemical 
characteristics  of  the  milk  (the  state  of  the  emulsion  of  the 
fat-molecules)  are  not  affected  by  such  manipulations  so  as 
to  render  Laboratory  Milk  more  difficult  of  absorption  and 
assimilation;  in  other  words,  we  may  question  whether  the 
milk  has  not  lost,  to  some  extent  at  least,  its  vital  character- 
istics. However  this  may  be,  the  clinical  experience  with  Labo- 
ratory Milk  of  such  well-known  pediatrists  as  Jacobi,  Starr, 
and  Koplik  has  been  of  such  a  character  as  to  modify  the 
enthusiasm  with  which  this  product  was  first  received.  On 
the  other  hand,  Eotch,  Holt,  Northrup,  and  many  other  com- 
petent observers  are  firm  believers  in  the  value  of  Laboratory 
Milk.  The  advocates  of  this  method  of  feeding  can  find  no 
proof  that  the  emulsion  of  the  fat  is  in  any  way  affected  by 
the  manipulations  in  the  laboratory.  We  may  perhaps  best 
summarize  the  situation  by  stating  that  Laboratory  Milk  repre- 
sents a  great  advance  in  modern  methods  of  feeding;  it  is 
successful  in  a  large  proportion  of  cases  when  sufficient  ex- 
perience with  its  proper  application  has  been  gained,  but  it 
fails  in  a  certain  percentage  of  cases,  even  in  the  best  hands. 
Intelligent  home  modification  of  milk  still  remains  our  chief 
resource  for  the  feeding  of  the  great  majority  of  infants,  since 
the  expense  of  the  laboratory  product  puts  it  out  of  the  reach 
of  all  but  the  well-to-do. 

One  great  advantage  of  the  Milk-Laboratory  to  the  com- 
munity consists  in  the  fact  that  it  furnishes  a  pure  product 
of  known  and  definite  composition.  The  standard  required 
for  Walker-Gordon  milk  has  already  served  to  excite  competi- 
tion among  milk  dealers  and  has  increased  the  supply  of  milk 
suitable  for  the  purposes  of  infant  feeding.  It  has  also  drawn 
the  attention  of  the  public  to  the  necessity  for  hygienic  regu- 
lations controlling  the  purity  of  such  a  universally  used  food 
as  cow's  milk. 


PRINCIPLES   OF   INFANT   FEEDING.  281 

Under  these  six  headings  we  have  outlined  the  principal 
methods  in  use  at  the  present  day  for  the  feeding  of  healthy 
infants.  Before  deciding  what  plan  we  should  adopt,  we 
must  consider  what  are  the  food  requirements  of  the  indi- 
vidual infant.  This  we  know  to  be  a  variable  factor  depending 
on  the  child's  age,  weight,  rate  of  growth,  degree  of  muscular 
development,  etc.  The  previous  methods  of  feeding,  and  the 
existence  of  gastro-intestinal  catarrh  due  to  improper  selection 
of  the  child's  food,  must  also  be  taken  into  account  when  we 
are  estimating  the  infant's  actual  powers  of  digestion. 

The  regulation  of  the  quantity  of  food  to  be  given  at  each 
feeding  and  the  interval  between  meals  is  of  equal  importance 
with  the  decision  what  the  child's  food  shall  be.  Those  who 
advocate  high  proteid  mixtures  believe  that  the  infant  digests 
casein  slowly ;  they  therefore  prolong  the  pauses  between  feed- 
ings to  three  hours  or  even  longer  for  dyspeptic  as  well  as 
healthy  infants.  They  believe  that  small  quantities  of  milk 
mixtures  containing  high  proteid  percentages  will  be  better 
tolerated  than  weaker  mixtures  containing  an  excess  of  water. 
On  the  other  hand,  those  who  believe  in  greater  dilution  of 
the  milk  consider  that  it  is  better  to  feed  at  shorter  intervals 
(from  two  to  three  hours),  taking  care  not  to  give  the  child 
an  amount  of  fluid  in  excess  of  the  gastric  capacity.  Some- 
times a  failure  to  gain  in  weight,  in  the  absence  of  dyspeptic 
symptoms,  shows  the  necessity  of  increasing  the  total  quantity 
of  food  without  altering  the  strength  of  the  mixture,  in  order 
to  re-establish  the  nutritive  equilibrium. 

The  tables  of  Holt,  Rotch,  and  Pfaundler  (Chapter  IV.) 
should  be  consulted  in  order  to  determine  the  average  capacity 
of  the  stomach  at  different  periods  of  infancy. 

The  child's  age  is  a  good  general  guide  on  which  to  base 
the  amount  of  food  required,  but  it  must  not  be  forgotten  that 
there  are  many  children  in  whom  increase  in  gastric  capacity 
does  not  run  parallel  with  the  gain  in  age  or  the  increase  in 
weight;  in  these  cases  the  gain  in  body  length  may  serve  as  a 


282  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

guide  (Pfaundler).  Careful  clinical  observation  will,  how- 
ever, rarely  fail  to  determine  correctly  what  quantity  of  food 
the  infant  is  capable  of  digesting  successfully. 

We  must  next  decide  what  proportions  of  the  different  ele- 
ments of  milk  are  best  adapted  to  the  infant's  needs.  Perhaps 
the  most  important  question  is,  How  much  proteid  or  nitroge- 
nous food  shall  we  give? 

Proteids:    Casein  and  Albumin. 

In  spite  of  the  teachings  of  Heubner,  Czerny,  and  others, 
and  the  metabolism  experiments  of  Keller,  Heubner,  and 
Bendix,  which  seem  to  prove  the  contrary,  the  statement  must 
be  reiterated  that  the  chief  obstacle  to  success  in  the  hand 
feeding  of  infants  consists  in  the  difficulty  in  digestion  of  the 
casein  in  cow's  milk.  The  differences  in  the  behavior  of 
mother's  milk  casein  and  cow's  milk  casein,  when  introduced 
into  the  infant's  digestive  tract,  are  well  known.  The  former 
coagulates  in  small,  soft,  homogeneous  masses  which  are  readily 
penetrated  by  the  gastro-intestinal  juices  and  are  easily  re- 
dissolved,  while  the  latter  forms  large,  tough,  irregular  curds 
which  are  difficult  of  solution  and  are  often  passed  only  par- 
tially digested  through  the  intestinal  tract.  Moreover,  we 
must  emphasize  the  fact  that  mother's  milk  and  cow's  milk 
are  two  distinct  fluids  adapted  physiologically  to  widely  differ- 
ent purposes,  and  that  the  digestive  powers  of  the  babe  in 
arms  and  those  of  the  calf  are  very  unequal  factors. 

Since  no  amount  of  modification,  however  scientific,  can 
render  cow's  milk  exactly  like  mother's  milk,  it  is  well  to 
dismiss  from  our  minds  the  idea  that  all  we  have  to  do  is 
"to  imitate  maternal  conditions."  This  is  especially  true 
of  the  early  months  of  life,  when  great  and  irreparable  dam- 
age to  the  infant's  digestion  frequently  follows  and  is  the  direct 
result  of  faulty  methods  of  feeding.  Suppose  an  infant  three 
or  four  weeks  old  were  taken  from  the  breast  and  given  a 
milk  mixture  imitating  in  composition  the  natural  secretion 


PRINCIPLES   OF   INFANT   FEEDING.  283 

at  this  period  of  lactation.  We  would  then  constitute  the 
child's  food  as  follows:  proteids  from  one  and  three-quarters 
to  two  per  cent.,  fat  from  three  to  four  per  cent.,  sugar  six 
per  cent.,  and  salts  0.2  per  cent.  Certainly  there  are  not  many 
infants,  even  if  we  include  those  with  unusually  well-developed 
powers  of  digestion,  who  are  capable  of  digesting  a  mixture  of 
this  composition  without  harm  at  this  period  of  life.  Therefore, 
when  we  have  to  feed  infants  on  cow's  milk,  the  essential  to 
success  is  that  the  child's  g astro-intestinal  tract  he  gradually 
accustomed  to  the  digestion  of  cow's  milk  casein.  If  the  first 
steps  in  this  process  of  education  are  correctly  carried  out, 
the  infant  will  soon  acquire  the  power  to  digest  relatively 
large  amounts  of  cow's  milk  proteids.  Should  the  first  steps 
be  wrong,  however,  incalculable  injury  will  result  which  may 
take  months  or  even  years  to  remedy. 

As  a  general  rule,  when  we  first  administer  cow's  milk  to 
the  infant,  it  is  well  to  reduce  the  proteids  to  rather  low  pro- 
portions (one  per  cent,  or  less).  If  this  is  necessary  when  we 
are  weaning  the  breast-fed  child  who  is  nine  months  or  one 
year  old,  it  becomes  imperative  when  we  have  to  feed  an  infant 
under  three  months  of  age  for  whom  the  maternal  nourish- 
ment has  failed.  In  such  a  case  our  choice  will  usually  lie 
between  two  methods.  Either  we  may  reduce  the  proportion 
of  casein  in  cow's  milk  by  dilution  until  a  percentage  is  reached 
which  the  child  is  able  to  digest  (this  will  vary  from  one 
per  cent,  for  healthy  infants  during  the  first  month  to  as  low 
as  0.50  per  cent,  or  even  0.25  per  cent,  for  the  new-born  and 
those  who  are  delicate  or  have  weak  digestions),  or  as  an 
alternative  we  may  use  peptonized  milk,  modified  by  the  ad- 
dition of  cream  and  diluents.  The  advantage  of  this  method 
of  feeding  is  that  it  enables  us  to  give  the  infant  a  larger 
amount  of  proteids  than  he  would  be  able  to  digest  in  the 
raw  state.  For  a  new-born  infant  the  proportions  of  our 
peptonized  milk  mixture  should  be  about  one  per  cent,  pro- 
teids, from  two  to  two  and  a  half  per  cent,  fat,  and  six  per 


284  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

cent,  sugar.  If  this  is  well  tolerated,  the  strength  of  the 
mixture  may  be  increased  to  one  and  a  half  per  cent,  proteids, 
three  per  cent,  fat,  and  six  per  cent,  sugar  at  the  end  of  the 
fifth  or  sixth  week.  If  it  is  desirable  to  continue  this  mode  of 
feeding  during  the  third  and  fourth  months,  the  proportions 
may  be  increased  to  proteids  two  per  cent.,  fat  three  and  a  half 
per  cent.,  and  sugar  seven  per  cent. 

It  must  be  understood  that  peptonization  is  only  a  temporary 
expedient,  and  that  it  is  inadvisable,  except  for  difficult  cases, 
to  continue  the  process  over  a  longer  period  than  two  or  three 
months.  By  gradually  reducing  the  time  of  peptonization, 
there  will  seldom  be  any  difficulty  in  replacing  this  food  with 
a  milk  mixture  containing  the  same  proportions.  It  is  well 
known  that  the  most  critical  period  in  the  life  of  the  arti- 
ficially fed  infant  is  the  first  three  months.  During  this  time, 
therefore,  the  proportion  of  casein  in  the  infant's  diet  {unless 
it  is  peptonized)  should  rarely  exceed  one  per  cent.  By  be- 
ginning with  low  proportions  of  casein  and  gradually  in- 
creasing the  proteid  strength  of  the  mixture  we  can  accustom 
the  child  to  its  digestion,  so  that  the  average  healthy  infant 
in  fair  hygienic  surroundings  will  thrive  at  the  age  of  six 
months  on  a  mixture  containing  from  one  and  a  half  to  two 
per  cent,  proteids,  and  at  the  age  of  from  twelve  to  sixteen 
months  will  be  able  to  take  whole  milk. 

Delicate  infants  with  weak  digestion,  cases  of  malnutrition, 
and  the  like  generally  require  dilute  mixtures  with  low  pro- 
teids. For  them  we  must  increase  the  proteid  percentages 
slowly  and  cautiously,  since  they  cannot  digest  the  proportions 
of  proteids  suitable  for  healthy  infants  until  a  much  later 
period  of  life. 

There  are  some  infants  who  seem  unable  to  digest  more  than 
minimal  amounts  of  cow's  milk  proteids  and  fats,  so  that  any 
attempt  to  increase  the  strength  of  the  milk  mixture  in  order 
to  maintain  the  proper  nutritional  equilibrium  is  followed 
by  gastro-intestinal   disturbances.     In  these   cases   we  must 


PRINCIPLES   OF   INFANT   FEEDING.  285 

resort  to  peptonized  milk,  whey-cream  mixtures,  egg  albumin, 
beef  juice,  meat  broths,  dextrinized  attenuants,  etc.;  or  we 
may  use  such  preparations  as  Steffen's  veal  broth,  Gregorys 
malt  soup,  or  somatose  milk.  Pure  buttermilk  is  said  to  be  suc- 
cessful in  a  certain  proportion  of  cases  (see  page  113).  When 
the  infant's  digestion  has  regained  to  some  degree  its  normal 
powers,  we  should  again  try  to  feed  the  child  on  plain  mixtures 
of  milk  and  cream.  Exceptionally  we  meet  cases  in  which 
even  such  mixtures  are  not  tolerated  before  the  end  of  denti- 
tion; the  selection  of  the  proper  food  then  becomes  a  problem 
of  great  difficulty. 

Fat. 

The  fat  of  cow's  milk,  like  the  casein,  is  less  easily  assimi- 
lated than  the  same  ingredient  in  mother's  milk.  It  stands 
next  to  casein  in  difficulty  of  digestion.  We  know  (see  Chapter 
IV.)  that  there  is  always  an  excess  of  fat  excreted  in  the 
faeces,  and  that  this  condition  may  become  pathologically  ex- 
aggerated until  actual  enteritis  results  (Biedert's  fat  diar- 
rhoea). In  deciding,  then,  what  percentage  of  fat  must  be 
given  in  the  infant's  food,  we  must  bear  in  mind  that  moder- 
ate rather  than  high  percentages  usually  give  the  best  results. 
Two  per  cent,  of  fat  may  safely  be  administered  to  the  new- 
born child,  and  the  percentage  may  be  soon  increased  to  three, 
provided  the  infant  is  healthy  and  has  a  vigorous  digestion. 
During  the  first  four  or  five  months  of  the  child's  life  it  is 
rarely  necessary  to  reduce  the  percentage  of  fat  below  two, 
and  rarely  advisable  to  exceed  the  limit  of  three  and  a  half. 
In  some  cases  it  is  permissible  to  increase  the  proportion  of 
fat  to  four  per  cent,  during  the  second  half  of  the  first  year; 
for  the  great  majority  of  infants,  however,  the  limit  of  three 
and  a  half  per  cent,  of  fat  had  best  not  be  exceeded  until  the 
child  is  put  on  a  diet  of  whole  milk. 

It  is  evident,  then,  in  considering  the  question,  How  much 
fat  does  the  infant  require?  that  we  are  unable  to  imitate 
very  closely  maternal  conditions.     While  the  healthy  breast- 


286  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

fed  infant  can  digest  and  assimilate  large  amounts  of  fat 
(four  per  cent,  and  over),  even  in  the  first  months  of  life, 
the  bottle-fed  baby  can  rarely  take  with  advantage  more  than 
three  per  cent,  of  fat  at  the  same  period;  sometimes  even  this 
amount  will  not  be  tolerated. 

The  success  with  which  some  babies  are  raised  on  a  diet 
of  condensed  milk  or  cow's  milk  simply  diluted  with  water 
would  seem  to  indicate  that  certain  children  thrive,  for  a  time 
at  least,  on  low  fat  percentages.  Such  cases  must  be  the 
exceptions,  however.  They  often  show  subsequently  signs  of 
improper  nutrition  (rickets,  anaemia,  scurvy,  excessive  fat 
deposits,  etc.).  The  rapidly  growing  organism  requires  a 
plentiful  supply  of  fuel,  which  is  furnished  it  in  the  hydro- 
carbons and  carbohydrates,  while  the  larger  part  of  the  nitro- 
gen serves  to  build  up  the  rapidly  growing  muscular  system. 
The  starches  and  fats  thus  diminish  the  consumption  of  ni- 
trogen, and  may  be  considered  "  nitrogen-savers." 

The  proportion  of  the  nitrogenous  to  the  non-nitrogenous 
elements  in  the  infant's  diet  is  a  matter  of  great  importance. 
We  must  not  overlook  the  fact  that  the  average  ratio  of  these 
elements  in  the  child's  natural  food  (the  breast-milk)  is  about 
one  nitrogenous  to  seven  and  a  half  non-nitrogenous,  whereas 
in  cow's  milk  the  average  ratio  is  about  one  of  the  former 
to  two  and  a  half  of  the  latter.  In  a  rough  way  we  may 
estimate  that  mother's  milk  contains  twice  as  much  fat  as 
proteids  and  four  times  as  much  sugar.  On  the  other  hand, 
cow's  milk,  when  undiluted,  contains  almost  equal  propor- 
tions of  proteids,  fat,  and  sugar;  hence  the  non-nitrogenous 
elements  constitute  not  much  more  than  twice  the  nitrogenous, 
whereas  the  "nitrogen-savers"  of  mother's  milk  exceed  the 
nitrogen-carrying  elements  more  than  seven  times.  The  im- 
portance, therefore,  of  a  sufficient  supply  of  fat  and  sugar 
for  the  proper  growth  of  the  infant  can  scarcely  be  over- 
estimated, since  that  child  will  thrive  best  in  whose  diet  the 
different  food  elements  properly  balance  one  another.      Yet 


PRINCIPLES   OF   INFANT   FEEDING.  287 

some  authorities  on  children's  diseases  still  recommend  plain 
dilutions  of  milk  with  water  which  neither  satisfy  the  normal 
requirements  of  the  infant  nor  allow  full  play  for  its  meta- 
bolic activities. 

We  may  supply  the  deficiency  in  fat  caused  by  dilution 
in  either  of  two  ways:  by  adding  fat  directly  to  the  milk 
mixture  in  the  shape  of  cream  or  by  making  use  of  top  milk 
which  contains  a  fairly  large  proportion  of  gravity  cream. 
In  the  former  case  we  may  follow  the  method  in  vogue  at 
the  Walker-Gordon  Milk-Laboratory,  where  a  small  amount 
of  centrifugal  cream  with  high  fat  (and  low  proteid,  sugar, 
and  salt)  percentage  is  added  to  separated  milk  (a  solution 
containing  proteids,  sugar,  and  salts,  but  almost  no  fat) ;  in 
other  words,  we  mix  two  solutions,  one  with  high  fat  and 
the  other  with  high  proteid  content,  to  obtain  the  percentages 
we  desire;  or  we  can  add  cream  to  whole  milk,  according  to 
some  of  the  formulae  devised  by  Westcott,  Baner,  and  others 
(see  Chapter  XIII.) .  If  we  use  top  milk,  we  dilute  our  pro- 
teids  and  fat  at  the  same  time,  and  the  calculation  is  sim- 
plified. The  great  advantages  to  be  gained  from  the  use  of 
top  milk  are  that  the  natural  emulsion  of  the  fat  is  in  no 
way  disturbed,  and  that  the  same  relative  proportions  of 
proteids  to  fat  obtain  which  are  found  in  mother's  milk, — 
namely,  the  amount  of  fat  is  twice  or  three  times  that  of 
the  proteids.  The  objections  which  may  be  made  to  top  milk 
are  twofold.  First,  it  may  be  urged  that  there  is  great  lia- 
bility to  error  in  calculating  the  fat  percentage,  unless  fre- 
quent analyses  of  the  milk  are  made.  Secondly,  since  the 
milk  must  stand  for  a  long  time  (from  twelve  to  twenty-four 
hours)  before  the  gravity  cream  will  come  to  the  surface,  it 
will  almost  certainly  be  infected  by  the  bacteria  which  rise 
with  the  cream.  It  will  be  shown  in  the  next  chapter  that 
the  first  objection  may  prove  a  serious  one.  The  danger  of 
bacterial  contamination  will  be  slight  if  we  can  obtain  "  cer- 
tified" or  equally  pure  milk,  bottled  at  the  dairy  and  kept  below 


288  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

45°  F.  till  it  is  used;  if  desired,  this  milk  may  be  pasteurized 
immediately  after  milking. 

We  must  not  forget  that  ordinary  commercial  cream  is 
more  often  than  not  unfit  for  the  infant's  use.  Centrifugal 
cream  has  the  advantage  of  being  fresh;  it  is  still  open  to 
question,  however,  whether  the  mechanical  disturbance  caused 
by  separation  does  not  affect  its  digestibility  and  absorbability. 

Sugar. 
Sugar  is  the  only  carbohydrate  normally  present  in  milk. 
It  seems  probable  that  the  lactose  in  cow's  milk  is  not  identical 
with  that  of  mother's  milk.  This  difference  of  composition 
is  of  less  consequence  for  the  infant  than  the  differences  in 
the  fat  and  the  proteids,  since  milk-sugar  causes  serious  di- 
gestive disturbances  much  less  frequently  than  either  of  the 
other  constituents  of  milk.  The  majority  of  pediatrists  use 
lactose,  the  natural  sugar  of  milk,  for  the  purposes  of  infant 
feeding,  although  some  competent  observers  consider  cane- 
sugar  preferable.  Maltose  is  recommended  by  Keller.  During 
the  first  weeks  of  life  and  for  sick  or  delicate  infants  the 
proportion  of  sugar  in  the  milk  mixture  should  not  exceed 
five  per  cent.  Later  this  can  be  increased  to  six  or  seven  per 
cent.  If  there  are  digestive  disturbances,  the  quantity  of  sugar 
must  be  reduced.  When  the  administration  of  starchy  foods 
is  begun,  the  proportion  of  sugar  need  not  exceed  that  found 
in  whole  milk, — about  4.5  per  cent.  It  is  important  that  a 
pure  preparation  of  milk-sugar  be  used.  Holt  advises  that  it 
be  dissolved  in  boiling  water ;  it  must  be  prepared  freshly  each 
day  and  filtered  through  absorbent  cotton  before  it  is  used,  to 
remove  accidental  impurities. 

Salts. 
The  percentage  of  salts  present  in  milk  mixtures  is  usually 
disregarded,  since  it  is  considered  that  their  proportion  will 
not  be  reduced  below  that  of  mother's  milk  by  any  ordinary 


PRINCIPLES   OF   INFANT   FEEDING.  289 

degree  of  dilution.  It  is  true  that  the  salts  of  cow's  milk 
exceed  those  in  mother's  milk  over  three  times;  so  that  we 
may  dilute  cow's  milk  to  this  extent  and  still  have  about  the 
same  proportion  of  mineral  matters  as  is  present  in  mother's 
milk.  It  would  seem,  however,  from  Blauberg's  careful  study  of 
the  fasces  in  connection  with  Heubner's  metabolism  experiments, 
that  the  salts  of  cow's  milk  (undiluted)  are  not  so  well  assimi- 
lated as  those  of  mother's  milk,  and  that  it  is  doubtful  whether 
dilution  of  the  milk  compensates  for  this  difference.  Moreover, 
the  amount  of  sodium  chloride  in  cow's  milk  is  already  less 
than  that  in  mother's  milk;  hence  the  importance  of  adding 
salt  to  the  infant's  food,  a  point  to  which  Jacobi  has  long 
since  drawn  our  attention.  It  seems  probable,  too,  that  the 
breast-fed  infant  can  assimilate  phosphorus  more  completely 
than  the  artificially  nourished  child,  since  much  of  this  min- 
eral is  present  in  the  breast-milk  in  organic  .combinations 
which  seem  to  be  more  readily  absorbed. 

The  amount  of  calcium  salts  in  cow's  milk  is  half  again 
as  great  as  that  in  mother's  milk;  but  when  we  dilute  cow's 
milk  two  or  three  times,  the  proportion  of  lime  salts  falls 
decidedly  below  that  present  in  mother's  milk.  The  same  holds 
true  of  the  phosphates,  provided  any  considerable  degree  of 
dilution  is  practised.  In  the  present  state  of  our  knowledge, 
it  is  impossible  to  decide  absolutely  as  to  the  importance  of 
these  salts  in  the  infant's  metabolism. 

Starch. 
Most  authorities  favor  the  use  of  decoctions  of  cereals  as 
diluents,  believing  that  this  facilitates  the  digestion  of  casein, 
besides  adding  slightly  to  the  nutritive  value  of  the  milk  mix- 
ture. Undoubtedly  there  are  some  infants  who  cannot  digest 
any  form  of  starch  until  dentition  is  well  advanced,  but  it  is 
equally  true  that  a  larger  number  are  decidedly  benefited  by 
this  addition  to  their  food.  In  some  cases  starch  proves  to 
be   of  distinct  advantage  as  a  tissue-saver,   since   it   checks 

19 


290  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

albuminous  waste.  Again,  the  use  of  a  starchy  decoction 
before  the  administration  of  the  milk  mixture  often  seems 
materially  to  aid  in  the  digestion  of  the  proteids,  particularly 
when  there  is  a  tendency  to  gastric  intolerance  of  proteids 
due  to  rapid  curdling  (Holt).  When  the  administration  of 
carbohydrate  food  is  indicated  before  the  period  of  dentition, 
the  starch  may  be  dextrinized,  since  it  is  more  easily  digested 
in  this  form  and  possesses  greater  nutritive  value.  In  some 
of  the  best  infant  foods  on  the  market  practically  all  of  the 
starch  is  dextrinized ;  they  can,  therefore,  be  used  as  adjuvants 
to  milk  when  the  administration  of  starch  is  indicated. 

Whey. 

Monti  deserves  credit  for  calling  attention  to  the  importance 
of  whey  as  a  diluent  for  cow's  milk.  The  whey-proteids  are 
easily  digested ;  they  resemble  the  soluble  albumins  of  mother's 
milk  in  their  physical  and  chemical  properties,  and  the  re- 
placing of  a  portion  of  the  casein  of  cow's  milk  by  soluble 
albumin  in  this  form  has  proved  of  decided  value  for  the 
infant's  nutrition. 

The  amount  of  soluble  albumin  in  cow's  milk  is  estimated 
to  be  about  0.50  per  cent.,  while  the  total  whey-proteids  aver- 
age from  0.80  to  one  per  cent.  Thus  it  appears  that  these 
whey-proteids  comprise  not  only  the  soluble  albumin  in  cow's 
milk,  but  also  a  portion  of  the  casein  which  has  been  converted 
into  a  soluble  form  by  the  action  of  rennin.  By  the  use  of 
whey  instead  of  water  as  a  diluent  we  can  materially  increase 
the  proportion  of  whey-proteids  in  our  milk  mixture  and 
avoid  the  administration  of  large  amounts  of  casein.  Whey 
may  be  mixed  with  milk,  top  milk,  or  cream  in  any  desired 
percentage,  or  it  may  be  given  alone  to  premature  or  weak  in- 
fants; it  is  particularly  valuable  as  a  means  of  beginning  the 
administration  of  milk  after  an  acute  attack  of  indigestion. 
Whey-cream  mixtures  yield  a  much  finer  coagulum  than  plain 
milk  and  cream  mixtures  with  the  same  proteid  content. 


PRINCIPLES   OF   INFANT   FEEDING.  291 

Peptonized  Milk. 
The  indications  for  the  use  of  peptonized  milk  have  already 
been  given.  Milk  and  cream  may  be  mixed  in  any  desired 
proportion  and  the  process  of  peptonization  can  be  carried  out 
for  from  ten  minutes  to  half  an  hour  or  longer.  It  requires 
about  two  hours  to  completely  peptonize  milk.  The  use  of  pre- 
digested  milk  offers  disadvantages  in  that  this  food  does  not 
furnish  the  necessary  physiological  stimulus  to  the  infant's 
stomach,  since  it  is  offered  already  prepared  for  intestinal 
digestion  and  absorption.  Where  the  milk  is  only  partially 
peptonized,  this  objection  has  less  weight.  It  is  well  to  begin 
with  half  an  hour's  peptonization,  gradually  reducing  the 
time  as  the  infant's  digestive  powers  regain  their  normal  con- 
dition. 

Egg  Albumin. 

Ever  since  the  investigations  of  Lehmann  showed  the  pres- 
ence of  soluble  albumin  in  mother's  milk  various  methods  have 
been  devised  to  provide  a  substitute  for  this  easily  digestible 
constituent.  Hesse  was  the  first  to  use  egg  albumin  in  his 
infant  food.  Now  there  are  various  preparations  on  the  mar- 
ket which  base  their  claims  to  be  perfect  substitutes  for  the 
maternal  nourishment  on  the  presence  of  a  certain  amount 
of  white  of  egg.  Apart  from  the  question  of  its  digestibility, 
there  seems  to  be  some  reasonable  doubt  whether  egg  albumin 
is  sufficiently  well  assimilated  to  aid  very  materially  the  in- 
fant's nutrition.  At  the  same  time  it  serves  a  useful  purpose 
at  certain  critical  periods  when  the  administration  of  milk 
in  any  form  is  contraindicated.  Egg  albumin  may  be  given 
either  mixed  with  water  and  a  little  salt  or  added  to  various 
decoctions  of  starch,  meat  broths,  etc.  It  is  probably  inferior 
to  whey  in  nutritive  value. 

Beef  Juice,  Broths,  Peptonoids. 
Usually  these  preparations  are  not  added  to  the  infant's 
diet  till  the  time  of  weaning  or  at  the  end  of  the  first  year. 


292  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

Before  this  time  they  may  be  used  during  attacks  of  milk 
infection,  or  as  accessories  to  the  diet  in  cases  of  anaemia, 
rickets,  etc.  When  the  child  is  unable  to  digest  large  amounts 
of  casein,  beef  juice  and  broths  often  prove  of  great  service, 
since  they  furnish  proteids  and  salts  in  readily  assimilable 
form.  When  diarrhoea  exists,  mutton  broth  is  preferable  to 
veal  or  beef  broth.  The  concentrated  foods,  such  as  the  liquid 
peptonoids,  panopepton,  etc.,  prove  of  distinct  value  during 
gastro-intestinal  affections  when  all  milk  must  be  withheld. 
The  small  proportions  of  alcohol  they  contain  especially  com- 
mend them  in  those  cases  where  there  is  marked  constitu- 
tional depression. 

Lime-Water. 

The  addition  of  lime-water  to  cow's  milk  is  generally  con- 
sidered to  be  the  best  means  of  reducing  the  acidity  of  the 
latter.  The  greater  acidity  of  cow's  milk  as  compared  with 
mother's  milk  is  a  point  on  which  much  stress  has  been  laid; 
but  this  is  purely  a  relative  matter,  depending  on  the  care 
and  cleanliness  observed  in  the  handling  of  the  milk,  the 
number  of  lactic  and  other  acid-producing  bacteria  present, 
and  the  temperature  at  which  the  milk  is  kept  before  it  reaches 
the  consumer.  The  amount  of  lime-water  required  is  variously 
estimated  at  from  one-twentieth  to  one-fourth  the  total  quan- 
tity of  the  mixture.  For  "certified  milk"  the  proportion  of 
one-twentieth  will  be  sufficient,  but  if  any  marked  degree  of 
acidity  is  present  in  the  milk,  it  will  be  necessary  to  use  larger 
quantities  to  attain  our  purpose. 

The  use  of  lime-water  as  a  routine  practice  seems  hardly 
necessary  when  the  infant's  digestion  is  healthy  and  the  milk 
supplied  in  a  fresh  condition.  If  the  milk  mixture  is  steril- 
ized by  heat,  lime-water  must  be  added  subsequently. 

Weight. 
To  ascertain  whether  or  not  the  child  is  thriving  the  prac- 
titioner has  no  single  guide  of  greater  value  than  the  informa- 


PRINCIPLES   OF   INFANT   FEEDING.  293 

tion  obtained  by  weighing  the  infant  at  weekly  intervals. 
Eoughly  stated,  a  healthy  child  should  gain  from  six  to  seven 
ounces  a  week  during  the  first  three  months,  from  four  to  five 
ounces  a  week  between  the  fifth  and  the  seventh  months,  and 
from  two  to  three  ounces  a  week  between  the  ninth  and  the 
twelfth  months.  During  the  second  year  the  rate  of  gain  is 
approximately  from  one  and  a  half  to  two  ounces  a  week. 

Of  course  many  children  gain  irregularly  in  weight,  more 
especially  those  who  are  artificially  fed  on  an  ill-assorted 
variety  of  food.  Again,  a  child  may  increase  rapidly  in  weight 
during  one  week  and  make  little  or  no  gain  the  next,  and  still 
be  in  good  health.  However,  we  may  assume  that  a  fairly 
constant  rate  of  gain  is  the  normal  condition  of  the  infant, 
any  marked  departure  from  which  indicates  disturbance  of 
nutrition,  which,  again,  is  due  in  the  great  majority  of  in- 
stances to  faulty  methods  of  feeding. 

Sterilization  and  Pasteurization. 

A  question  which  will  infallibly  present  itself  to  the  prac- 
titioner concerning  the  preparation  of  the  milk  mixture  is 
whether  it  will  be  necessary  to  apply  heat  to  guard  against  the 
danger  of  milk  infection.  Our  decision  will  be  based  on  the 
condition  of  the  milk  when  it  reaches  the  consumer.  If  we 
are  able  to  obtain  pure  milk  which  can  be  kept  cold  before  and 
after  it  reaches  the  consumer,  and  if  there  is  little  or  no  dan- 
ger of  its  contamination  during  the  process  of  preparing  the 
infant's  food,  it  will  be  unnecessary  to  employ  any  method  of 
pasteurization  or  sterilization,  at  least  during  the  cool  months 
of  the  year. 

When  contamination  of  the  milk  has  already  occurred  or  is 
likely  to  occur  during  the  handling  it  undergoes  on  the  part 
of  the  mother  or  nurse,  it  becomes  almost  indispensable  to 
apply  heat  in  some  form  or  other.  The  degree  of  heat  neces- 
sary to  destroy  the  bacteria  present  in  milk  has  been  the  sub- 
ject of  much  debate.     It  is  almost  impossible  to  reconcile  the 


294  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

many  conflicting  statements.  We  must  remember,  though, 
that  many  of  these  assertions  are  not  based  on  the  results 
of  original  research,  but  are  copied  from  the  work  of  other 
investigators,  often  without  corroboration  of  the  methods  em- 
ployed. More  extended  observation  and  more  perfect  knowl- 
edge of  the  life-conditions  of  the  different  species  of  bacteria 
will  be  required  before  we  can  advocate  definite  degrees  of 
temperature  for  their  destruction  with  absolute  certainty  of 
success.  We  must  also  not  lose  sight  of  the  importance  of  the 
unorganized  ferments  present  in  milk;  since  they  play  a  role 
in  the  digestive  process,  their  destruction  by  heat  cannot  be 
regarded  as  immaterial  for  the  child's  welfare.  In  this  field 
we  have  probably  still  much  to  learn. 

From  the  evidence  at  hand,  without  being  able  to  add  the 
results  of  original  investigations,  we  have  attempted  to  specify 
what  we  may  expect  to  accomplish  by  the  application  of  heat, 
allowing  a  certain  range  in  the  degree  of  heat  to  be  used  to  com- 
pensate for  possible  errors.  Heating  from  60°  to  68°  C.  (140° 
to  155°  F.)  for  thirty  minutes  (the  milk  being  kept  in  closed 
bottles  to  prevent  the  formation  of  a  pellicle  on  the  surface) 
will  destroy  or  render  innocuous  the  tubercle  bacilli  and  the 
common  pathogenic  germs,  such  as  those  of  diphtheria  and 
scarlet  fever.  It  will  also  destroy  the  majority  of  the  lactic- 
acid-producing  bacteria.  This  temperature  will  not  destroy  the 
spore-bearing  butyric  and  peptonizing  bacteria  and  other  va- 
rieties which  under  certain  conditions  may  produce  lactic  acid. 
From  70°  C.  (158°  F.)  up  the  unorganized  ferments  will  be 
destroyed  and  the  milk  will  begin  to  undergo  certain  chemical 
and  physical  alterations  which  probably  render  it  less  easily 
digested  and  assimilated. 

It  is  important  to  remember  that  when  we  use  a  low  tem- 
perature (60°  C.)  the  skim  or  pellicle  which  forms  on  milk 
heated  in  uncovered  vessels  will  protect  the  bacteria  it  encloses 
in  its  meshes  and  prevent  their  destruction.  Heat  should  there- 
fore always  be  applied  to  the  milk  in  closed  vessels,  or  the  milk 


PRINCIPLES   OF  INFANT  FEEDING.  295 

should  be  kept  thoroughly  mixed  by  agitation  during  the 
process  of  heating.  If  we  wish  to  destroy  all  the  lactic-acid- 
producing  bacteria,  the  temperature  to  be  employed  should  be 
not  less  than  75°  C.  (167°  F.)  for  from  twenty  to  thirty 
minutes. 

When  the  milk  supplied  is  highly  contaminated,  it  must  be 
sterilized  at  100°  C.  (212°  F.)  for  at  least  thirty  minutes. 
If  it  is  not  possible  to  preserve  the  milk  at  a  low  temperature, 
more  especially  during  hot  weather  when  bacteria  multiply  so 
rapidly,  it  will  be  safer  to  repeat  the  process  of  heating  every 
six  hours.  Whatever  disadvantages  this  degree  of  heat  may 
entail  are  more  than  offset  by  the  advantage  of  destroying  all 
the  bacteria  with  which  the  milk  is  infected.  Such  milk,  even 
after  sterilization,  should  not  be  employed  for  the  infant's  use 
unless  milk  of  a  better  quality  cannot  be  obtained;  for  we 
know  that  the  spores  of  the  peptonizing  bacteria  are  not  de- 
stroyed even  by  temperatures  as  high  as  110°  C. ;  and  should 
conditions  favorable  for  their  development  be  present,  the  pep- 
tonizing bacteria  may  multiply  in  apparently  sterile  milk  and 
prove  a  grave  source  of  danger  for  the  infant. 


CHAPTEE    XIII. 
METHODS   FOR   THE   HOME   MODIFICATION   OF   MILK. 

There  are  two  methods  of  procedure  available  for  the  physi- 
cian who  proposes  to  feed  a  child  with  milk  modified  at  the 
home.  Either  he  may  prepare  and  modify  his  mixture  accord- 
ing to  the  clinical  evidence  afforded  by  the  state  of  the  child's 
digestion  and  nutrition,  disregarding  the  percentages  of  the 
ingredients,  or  he  may  begin  by  the  administration  of  a  formula 
representing  the  percentages  of  fat,  sugar,  and  proteids  suitable 
for  a  given  age  and  weight,  altering  them  at  will  as  the  needs 
of  the  case  demand,  but  always  having  at  least  an  approximate 
idea  of  the  strength  of  the  food  administered.  The  first  method 
is  empirical  and  easy  of  execution;  the  latter  is  quite  as  suc- 
cessful and  much  more  satisfactory.  A  good  example  of  the 
former  method  is  the  mixture  of  John  Forsyth  Meigs,  con- 
sisting of  equal  parts  of  barley-water,  lime-water,  milk,  and 
cream,  sweetened.  We  know  that  it  contains  about  two  per 
cent,  of  proteids  and  four  per  cent,  of  fat,  and  we  can  vary 
the  proportions  of  the  different  ingredients  from  time  to  time 
to  meet  the  clinical  indications.  Success  in  infant  feeding, 
then,  depends  quite  as  much  on  the  ability  to  correctly  inter- 
pret clinical  phenomena  as  on  the  selection  of  the  method,  pro- 
vided the  plan  of  feeding  adopted  be  not  too  rigid  to  allow  for 
the  wide  variations  in  the  digestive  capacity  of  the  infant. 

In  order  to  make  even  the  simplest  calculations  we  must  be 
familiar  with  the  percentages  of  the  different  ingredients  in 
whole  milk.  It  is  safe  to  assume  that  milk  of  good  quality 
will  contain  from  three  and  a  half  to  four  per  cent,  proteids, 
four  per  cent,  fat,  four  and  a  half  per  cent,  sugar,  and  0.7  per 
cent,  salts.*  The  average  milk  supplied  in  cities  will  contain  a 
lower  proportion  of  fat  than  the  above,  varying  from  three  to 

*See  page  326. 
296 


HOME   MODIFICATION   OF   MILK.  297 

four  per  cent.  The  simplest  method  of  feeding  is  to  dilute 
milk  with  water  or  barley-water  and  add  sugar;  examples  of 
this  are  Biedert's  milk  formulae  and  the  Heubner-Hoffmann 
Mixture.  To  ascertain  the  strength  of  our  milk  mixture  we 
divide  the  percentages  of  the  different  ingredients  by  the  degree 
of  dilution  employed.  If  we  add  two  parts  of  water  to  one  of 
milk,  we  dilute  the  milk  three  times  and  must  divide  by  three ; 
one  part  of  milk  to  three  of  water  gives  us  a  divisor  of  four, 
etc.  The  simplest  method  for  the  estimation  of  sugar  is  to 
ascertain  what  percentage  of  lactose  must  be  added  to  compen- 
sate for  the  degree  of  dilution  and  to  make  a  sugar  solution 
containing  this  percentage.  For  instance,  if  we  dilute  good 
milk  four  times,  our  mixture  will  contain  about  one  per  cent, 
proteids,  one  per  cent,  fat,  and  one  per  cent,  sugar.  To  pro- 
vide six  per  cent,  sugar  in  the  food  we  therefore  use  a  five 
per  cent,  sugar  solution  for  our  diluent,  made  by  dissolving 
one  ounce  of  sugar  (lactose)  in  twenty  ounces  of  water.  To 
provide  seven  per  cent,  sugar  a  six  per  cent,  solution  of  lac- 
tose is  made  by  adding  one  ounce  of  lactose  to  sixteen  and 
two-thirds  ounces  of  water.  For  practical  purposes  we  may 
estimate  that  three  level  tablespoonfuls  of  milk-sugar  equal 
one  ounce,  and  one  and  a  half  even  teaspoonfuls  equal  one 
drachm.  If  we  use  granulated  sugar,  two  level  tablespoonfuls 
equal  one  ounce  and  one  even  teaspoonful  equals  one  drachm. 
For  greater  accuracy  receptacles  of  known  capacity  must  be 
procured.  The  addition  of  starchy  decoctions,  such  as  barley-, 
rice-,  or  oatmeal-water,  adds  very  small  amounts  of  proteids 
and  fat  and  about  one  and  a  half  per  cent,  of  starch  to  the 
mixture.  The  sugar  solution  may  be  made  with  such  decoc- 
tions instead  of  plain  water.  Enough  must  be  prepared  each 
morning  to  supply  the  total  quantity  needed  during  the  day; 
during  the  summer  months-  it  will  be  safer  to  prepare  our  sugar 
solution  twice  a  day  to  insure  its  freshness. 

Since  it  is  impossible  by  simple  dilution  of  milk  to  obtain 
at  the  same  time  a  sufficiently  low  proportion  of  proteids  and 


298  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

a  sufficiently  high  proportion  of  fat,  it  becomes  necessary  to 
add  fat  to  the  diet  for  the  great  majority  of  cases.  Cream 
resembles  the  fat  of  mother's  milk  more  closely  than  any  other 
substitute  (such  as  butter,  cod-liver  oil,  etc.),  and  since  it  is 
also,  when  fresh,  more  readily  digestible  than  these  other 
forms  of  fat,  it  should  be  employed  for  the  purposes  of  infant 
feeding.  The  use  of  cream  is  associated  with  manifest  objec- 
tions. It  is  almost  sure  to  be  contaminated  with  bacteria, — 
in  commercial  gravity  cream  bacterial  decomposition  may  be 
well  advanced  during  the  summer  months, — it  is  very  com- 
monly adulterated  by  "  cream  thickener"  or,  worse,  by  preserv- 
atives, and,  finally,  the  percentage  of  butter  fat  can  rarely  be 
known  with  accuracy.  The  importance  of  obtaining  cream  that 
is  fresh  and  clean  can  scarcely  be  overestimated.  During  the 
hot  weather  of  our  American  summers  even  the  best  cream 
sours  very  readily.  Unless  we  can  obtain  it  from  a  thoroughly 
reliable  dealer,  and  unless  we  can  be  sure  that  it  will  be  kept 
at  a  sufficiently  low  temperature  (from  45°  to  50°  F.)  until 
it  is  used,  it  is  better  to  discard  the  use  of  cream  altogether 
during  the  summer  months.  Whenever  possible,  the  physician 
should  acquaint  himself  personally  with  the  methods  in  use  at 
the  dairy  from  which  the  milk  and  cream  for  the  infant's  diet 
are  procured,  since  it  is  only  thus  that  he  can  make  sure  that 
the  cream  is  fit  for  use  (unless  he  can  obtain  "  certified  milk") . 
During  the  summer  months  he  should  employ  only  freshly 
centrifugated  cream,  or  gravity  cream  which  has  been  cooled 
immediately  after  milking  and  kept  below  50°  F.  during  the 
time  it  is  raising. 

There  still  remains  to  be  decided  the  question:  How  much 
fat  is  present  in  the  cream  we  are  using  ?  Chapin's  and  Holt's 
tables  give  us  estimates  of  the  cream  in  top  milk  and  will  be 
discussed  later.  We  have  no  means  of  knowing  the  exact  per- 
centage of  fat  in  ordinary  gravity  or  centrifugal  cream,  unless 
the  dealer  is  willing  to  furnish  a  fat  analysis.  Commercial 
cream  usually  contains  from  twelve  to  sixteen  per  cent,  of 


HOME  MODIFICATION   OF  MILK.  299 

butter  fat;  this  variation  is  so  great  that  it  renders  accuracy 
in  the  calculation  of  formulas  impossible.  If  we  wish  to  know 
exactly  how  much  fat  we  are  giving  the  child,  analysis  of  the 
cream  becomes  indispensable.  Eight  per  cent.,  twelve  per  cent., 
and  sixteen  per  cent,  cream  may  be  used  in  preparing  our  mix- 
tures, also  centrifugal  cream  containing  still  higher  fat  per- 
centages. The  higher  the  proportion  of  fat  the  lower  will  be  the 
proportion  of  the  other  ingredients. 

The  following  table  has  been  used  as  a  basis  for  making 
various  formulae,  such  as  Westcott's,  Baner's,  etc.  In  his  latest 
edition  Holt  states  that  the  figures  for  the  proteids  are  too 
high  (see  page  131). 

Fat.  Proteids.       Sugar.  Salts. 

Per  cent.     Per  cent.     Per  cent.      Per  cent. 
Whole  milk  or  four  per  cent,  cream 

gives 4  4.00  4.50  0.70 

Eight  per  cent,  cream  gives 8  4.00  4.40  0.70 

Twelve  per  cent,  cream  gives 12  3.80  4.20  0.64 

Sixteen  per  cent,  cream  gives 16  3.60  4.00  0.60 

Twenty  per  cent,  cream  gives 20  3.20  3.80  0.55 

Thirty-two  per  cent,  cream  gives 32  2.80  3.20  (?)  0.40  (?) 

By  simple  dilution  of  cream  with  a  sugar  solution  of  the 
desired  strength  we  can  prepare  various  mixtures  of  high  fat 
content.  For  instance,  by  mixing  one  part  of  twelve  per  cent, 
cream  and  three  parts  of  water  we  get:  fat  three  per  cent., 
proteids  0.90  per  cent.,  sugar  1  per  cent.,  and  salts  0.15  per 
cent.  The  sugar-water  should  then  be  of  five  per  cent,  strength 
to  give  a  total  of  six  per  cent,  in  our  mixture.  By  mixing  one 
part  of  eight  per  cent,  cream  with  three  parts  of  five  per  cent, 
sugar  solution  we  get :  fat  two  per  cent.,  proteids  one  per  cent., 
sugar  six  and  one-tenth  per  cent.,  and  salts  0.17  per  cent.  An 
eight  per  cent,  cream  can  be  obtained  by  mixing  one  part  of  six- 
teen per  cent,  gravity  cream  and  two  parts  of  whole  milk,  or 
one  part  of  twenty  per  cent,  centrifugal  cream  and  three  parts 


300  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

of  whole  milk.  A  twelve  per  cent,  cream  can  be  made  by 
mixing  two  parts  of  sixteen  per  cent,  gravity  cream  and  one 
part  of  whole  milk,  or  equal  parts  of  twenty  per  cent,  centrifu- 
gal cream  and  wjiole  milk  (Holt). 

These  simple  dilutions  of  cream  with  sugar  solution  are  easy 
to  prepare  and  will  prove  serviceable  in  many  cases.  We  may 
raise  one  objection  to  them, — namely,  that  the  proportion  of 
fat  and  proteids  must  be  increased  and  decreased  together, 
since  the  ratio  of  fat  to  proteids,  using  eight  per  cent,  and 
twelve  per  cent,  cream,  must  be  either  two  to  one  or  three  to 
one.  To  meet  this  objection  we  must  employ  either  milk  or 
whey  in  preparing  our  mixtures.  Egg  albumin  has  not  proved 
a  satisfactory  substitute  for  the  proteids  of  milk,  except  as  a 
temporary  expedient  in  cases  of  digestive  disturbance  when  all 
milk  must  be  withheld. 

Various  mathematical  formulae  have  been  devised  for  esti- 
mating the  quantity  of  whole  milk  and  cream  required  to  give 
us  definite  milk  formula?.  The  first  of  these  was  published  by 
Thompson  S.  Westeott,  of  Philadelphia,  in  January,  1898; 
following  this,  in  March,  1898,  William  L.  Baner,  and  in  May, 
1898,  Henry  L.  Coit  published  their  methods.  In  March,  1899, 
F.  Lewis  Taylor  generalized  the  previous  calculations;  "his 
formulae  must  be  accepted  as  the  groundwork  of  every  system 
of  calculation  for  percentage  formulae"  (Westeott).  Shriner 
has  also  devised  a  method  of  calculating  percentages  similar 
to  that  in  use  at  the  Walker-Gordon  Laboratory.  Henry  L. 
Coit,  in  the  Archives  of  Pediatrics  for  May,  1898,  describes 
his  method  for  the  home  modification  of  cow's  milk,  using  a 
decinormal  cream  solution  for  the  fat,  a  saccharated  skimmed 
milk  solution  for  the  proteids  not  in  the  cream,  and  a  standard 
sugar  solution  for  the  lactose  not  in  either  of  the  above.  The 
practical  application  of  this  method  is  difficult. 

Baner's  formulas  for  the  home  modification  of  milk,  pub- 
lished in  the  New  York  Medical  Journal,  March  12,  1898,  are 
simple  and  easily  remembered. 


HOME   MODIFICATION   OF   MILK.       i  301 

Given : 

The  quantity  desired  in  ounces Q 

The  desired  percentage  of  fat F 

The  desired  percentage  of  sugar S 

The  desired  percentage  of  proteids P 

To  find  (in  ounces)  : 

Cream  (16  per  cent.) =  Q  X  (f  —  P) 

Milk =  S. X_P  _  c 

4 

Water =  Q  —  (C  +  M) 

Lactose =  (S~P)XQ       - 

100 

Tf  20  per  cent,  centrifugal  cream  were  used,  the  denominator  would 
be  16. 

If  12  per  cent,  were  used,  it  would  he  8. 

Example. — To  provide  twenty-four  ounces  of  a  mixture  con- 
taining one  per  cent,  proteids,  three  per  cent,  fat,  and  six  per 
cent,  sugar: 

94 

Cream  (16  per  cent.  )  =  ~X(3  —  1)  =  2  X  2    =    4  ounces 

Milk =  ?AXJ  _4     =6_4    =    2  ounces 

4 

Diluent =  24  —  (4  -f  2)  =  24  —  6  =  18  ounces 

Sugar ==(6-l)X24  =  5Xj_4^       QUnces 

5  100  100  * 

Thompson  S.  Westcott,197  in  an  elaborate  monograph  on 
the  scientific  modification  of  milk,  published  in  International 
Clinics,  October,  1900,  has  considered  at  some  length  the 
question  of  milk  modification  by  mathematical  formulae.  We 
have  selected  only  those  which  are  adapted  to  general  use,  and 
must  refer  the  reader  to  the  original  article  for  more  extensive 
knowledge  on  the  subject. 

To  determine  the  quantities  of  cream,  milk,  lactose,  and 


302  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

water  for  a  given  formula :  C  =  cream,  M  =  milk,  F  =  fat, 
P  sss  proteids,  L  =  lactose,  T  =  total  quantity,  S  ==  sugar  per- 
centage desired. 

C  = (F-P)Q 

8.2  (12  <fc  cream)  or  12.4  (16  <f0  cream)  or  16.8  (20  <fc  cream) 
M  =  §1  _  3  C  (12  f0  )  or  4  0  (16  <?0  )  or  5  C  (20  </0  ) 

L=:QS— 4.3(M+  C) 
100 

If  twenty  ounces  of  a  mixture  be  desired,  containing  three 
per  cent,  fat,  six  per  cent,  sugar,  and  two  per  cent,  proteids, 
using  sixteen  per  cent,  cream,  the  formula  would  read : 

c  =  (3-2)20  =  J0_  =  15ounce8 
12.4  12.4 

M  =  20_>^3  _4XL6=60_6==:9  ounces 
4^4 

L  =  20X6-4.8(9+1.5)  =  120z=46=|ounce 
100  100  4 

Conversely,  in  order  to  determine  the  percentage  of  ingredients 
in  any  combination  of  cream,  milk,  and  sugar,  Westcott  sug- 
gests the  following : 


To  find 

percentage  of  fat : 

^X  16  (or  12): 

=  fat 

percentage 

from  cream 

Q  A 

=  fat 

percentage 

from  milk 

Sum  of  these      =  total  fat  percentage  in  mixture 

To  find  percentage  of  proteids  : 

C 

—  X  3.6  (16  ^  )  or  3.8  (12  fc)  =  proteid  percentage  from  cream 
Q 

M 

—  X  4  =  proteid  percentage  from  milk 

Sum  of  these  =  total  proteid  percentage  in  mixture 

a                     ,             100  L  + 4.3  (M  +  C) 
Sugar  percentage  = ! — — -* 1 ' 

Q 


HOME   MODIFICATION   OF   MILK.  303 

For  instance,  taking  the  same  mixture  as  above  determined, — 
namely,  one  and  a  half  ounces  of  sixteen  per  cent,  cream,  nine 
ounces  of  milk,  three-quarters  of  an  ounce  of  lactose,  and  nine- 
teen and  a  half  ounces  of  water : 

i£xi6  =  1.2 

JLx    4=L8 

20  3.0  per  cent,  total  fat 

Mv3.6=    .27 
20  ^ 

JLx     4  =  1.80 

20  

2.07  per  cent,  total  proteids 

100  X- 76  +  4.8X10.5  =  75  +  45.15  =  ,  per  cent  6ugar 

Westcott  has  also  published  formulae  for  mixtures  of  sepa- 
rated milk  and  centrifugal  cream.  Unless  we  wish  to  obtain 
either  very  low  or  very  high  fat  percentages,  mixtures  of  cream 
and  whole  milk  are  all  that  is  necessary. 

Edward  Hamilton,  in  the  American  Journal  of  Obstetrics, 
October,  1901,250  describes  a  method  based  on  the  fact  that 
ordinary  cream,  milk,  and  skimmed  milk  contain  relatively  the 
same  amount  of  proteids  and  salts,  and  that  cream  is  simply 
a  superfatted  milk.  If  we  multiply  the  quantity  of  milk  mix- 
ture to  be  used  by  the  percentage  of  fat  desired  and  divide  by 
the  percentage  of  fat  in  the  cream  used,  we  obtain  the  amount 
of  cream ;  if  we  multiply  the  quantity  of  milk  mixture  by  the 
percentage  of  proteids  desired,  divide  by  four  (the  percentage 
of  proteids  in  skimmed  milk),  and  subtract  from  this  result 
the  amount  of  cream  previously  determined,  we  obtain  the 
amount  of  skimmed  milk  needed.  The  quantity  of  the  milk 
mixture  less  the  amount  of  cream  and  skimmed  milk  will  equal 
the  amount  of  the  diluent  to  be  used.  Three  drachms  (one 
level  tablespoonful)  of  lactose  must  be  added  to  each  ten  ounces 
of  the  mixture ;  lime-water  or  soda  may  be  used  to  reduce  the 
acidity. 


304  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

Example. — Forty  ounces  of  mixture  desired:  fat  four  per 
cent.,  sugar  seven  per  cent.,  proteids  two  per  cent,  (sixteen  per 
cent,  cream  to  be  used) . 

40  X  4  -*-  16  =  10  ounces  cream 
40  X  2  -f-  4  =  20  —  10  =  10  ounces  of  skimmed  milk 
40  —  20  =  20  ounces  diluent 
Sugar  =  four  level  tablespoonfuls 
Lime-water  q.s. 
This  method  seems  to  be  an  adaptation  of  Baner's  formula, 
using  skimmed  milk  in  place  of  whole  milk. 

The  advantages  of  adding  whey  to  milk  or  cream  mixtures 
have  already  been  considered.  We  are  enabled  to  combine  the 
digestible  whey-proteids  with  the  proteids  and  fat  of  cream  or 
milk,  thereby  greatly  lowering  the  proportion  of  coagulable  to 
non-coagulable  proteids. 

Practically,  three  methods  may  be  employed  in  the  prepara- 
tion of  whey. 

1.  Simple  coagulation  with  rennet  or  essence  of  pepsin, 
avoiding  subsequent  agitation  of  the  curd,  the  fluid  being 
allowed  to  separate  solely  by  gravity.  Whey  so  prepared  will 
contain  practically  all  the  salts  and  sugar  of  the  milk,  a  mini- 
mum of  casein,  a  small  amount  of  fat,  and  all  of  the  soluble 
albumin  (Monti).  Its  composition  may  be  estimated  at: 
whey-proteids  from  0.85  to  one  per  cent.,  fat  0.33  to  0.50  per 
cent.,  sugar  4.50  per  cent.,  salts  0.18  per  cent. 

2.  After  coagulation  the  curd  may  be  thoroughly  beaten  until 
disintegrated  and  the  fluid  contents  expressed  by  straining 
forcibly  through  several  layers  of  cheese-cloth.  This  is  again 
strained  to  remove  the  fine  casein  flakes  which  were  forced 
through.  This  preparation  will  contain  more  fat  (perhaps  as 
much  as  one  per  cent.)  and  slightly  more  casein  than  whey 
separated  by  the  preceding  method. 

3.  Like  the  second  method,  except  that  the  casein  flakes  are 
not  strained.  A  small  amount  of  casein  may  thus  be  adminis- 
tered in  a  readily  assimilable  form. 


HOME   MODIFICATION   OF   MILK.  305 

An  objection  to  the  use  of  whey  is  the  expense  of  preparing 
it,  but  if  we  remove  the  top  milk  from  a  quart  bottle,  we  can 
usually  obtain  enough  whey  from  what  remains  for  the  purpose 
of  dilution.  Before  adding  whey  to  cream  or  milk,  it  should 
be  heated  to  65°  C.  (150°  F.)  in  order  to  destroy  the  rennet 
enzyme.  At  70°  C.  (160°  F.)  the  soluble  albumin  begins  to 
coagulate. 

Kotch  says  that  it  is  cheaper  to  prepare  whey  from  fat-free 
milk. 

Konig's  analysis  of  whey  (proteids  0.86  per  cent.,  fat  0.32 
per  cent.,  sugar  4.79  per  cent.,  salts  0.15  per  cent.)  was  used 
by  Westcott  in  preparing  the  following  tables  of  whey-cream 
mixtures.  Other  authorities  have  found  as  high  as  one  per 
cent,  of  whey-proteids,  while  Monti  asserts  that  whey  contains 
as  high  as  one  per  cent.  fat.  This  percentage  of  fat  is  probably 
obtained  by  a  method  similar  to  No.  2. 

Quantity  of  cream  to  be  used  in  a  twenty-ounce )                    .      .             _.  Propria 

mixture  with  whey.                         J lo  glve          * at*  noteias. 

Per  cent.  Per  cent. 
Twenty  per  cent,  cream. 

0. 70  ounce 1.00  0.94 

1.71  ounces 2.00  1.06 

2.72  ounces 3.00  1.18 

3.74  ounces 4.00  1.30 

Sixteen  per  cent,  cream. 

0.87  ounce 1.00  0.98 

2.14  ounces 2.00  1.15 

3.42  ounces 3.00  1.32 

4.69  ounces 4.00  1.50 

Twelve  per  cent,  cream. 

1.16  ounces 1.00  1.03 

2.88  ounces 2.00  1.28 

4.59  ounces 3.00  1.53 

6.30  ounces ! 4.00  1.79 

20 


306  THE   ARTIFICIAL   FEEDING   OF  INFANTS. 

Eight  per  cent,  cream. 

1.77  ounces 1.00  1.13 

4.38  ounces 2.00  1.53 

6.98  ounces 3.00  1.92 

9.58  ounces 4.00  2.32 

Four  per  cent,  cream  (whole  milk). 

3.69  ounces 1.00  1.44 

9.13  ounces 2.00  2.29 

14.56  ounces 3.00  3.15 

20.00  ounces 4.00  4.00 

The  only  objection  to  the  use  of  such  tables  is  that  they  can 
scarcely  be  memorized  and  may  not  be  available  when  needed. 
The  simplest  method  of  determining  the  proportions  in  a  whey- 
cream  mixture  is  to  add  the  percentages  of  the  different  ingre- 
dients, dilute  with  plain  water  or  barley-water,  and  divide  by 
the  degree  of  dilution. 


Fat. 

Proteids. 

Sugar. 

Salts. 

Per  cent. 

Per  cent. 

Per  cent. 

Per  cent. 

Sixteen  per  cent,  cream  | 

'one 

part)  = 

16.00 

3.60 

4.00 

0.60 

Whey  (one  part) 

= 

0.50 

1.00 

4.50 

0.18 

Water  ( three  parts ) 

Total  (five  parts) 

_ 

16.50 

4.60 

8.50 

0.78 

Diluting  with  three  parts  of  water  and  dividing  by  five,  we 
get  a  mixture  composed  as  follows :  fat  3.3  per  cent.,  proteids 
0.92  per  cent.,  sugar  1.70  per  cent.,  and  salts  0.15  per  cent. 
We  must  then  add  enough  sugar  to  our  mixture  to  bring  the 
sugar  percentage  up  to  six  or  seven.  For  instance,  if  we  wish 
to  prepare  a  whey-cream  mixture  containing  0.92  per  cent, 
proteids,  3.3  per  cent,  fat,  0.15  per  cent,  salts,  and  six  per 
cent,  sugar,  we  must  dilute  with  a  seven  per  cent,  sugar  solu- 
tion. The  amount  of  su'gar  present  in  the  cream  will  then  be 
represented  by  four,  that  in  the  whey  by  4.5,  and  that  in  three 


HOME   MODIFICATION   OF   MILK.  307 

parts  of  seven  per  cent,  sugar  solution  by  twenty-one  (3  X  7  = 
21).  Adding  these  figures,  we  obtain  29.50,  which  must  be 
divided  by  the  degree  of  dilution  (five)  to  give  us  the  amount 
of  sugar  present, — almost  six  per  cent. 

Another  method  of  bringing  up  the  sugar  percentage  to  the 
desired  strength  is  simply  to  add  sugar  to  the  total  quantity  of 
the  mixture.  For  example,  twenty-five  ounces  of  the  above 
mixture,  when  prepared  with  plain  water,  will  contain  1.7  per 
cent,  sugar.  By  adding  one  ounce  of  lactose  to  twenty-five 
ounces  of  water  .we  increase  the  sugar  percentage  of  our  mixture 
by  four  (4  +  1.7  —  5.7  per  cent,  sugar). 

To  prepare  two  ounces  of  a  whey-cream  mixture  containing 
1.5  per  cent,  proteids,  1.5  per  cent,  fat,  and  five  per  cent,  sugar, 
add  two  drachms  of  eight  per  cent,  cream  to  fourteen  drachms 
of  whey.  We  thus  dilute  our  cream  eight  times,  and  must 
divide  by  eight  to  obtain  the  percentage  of  fat,  proteids,  and 
sugar  represented  by  the  cream. 

Fat. 
Per  cent. 

Cream  (eight  per  cent.)  contains 8  )  8.00 

1.00 
Whey  contains 0. 50 


Proteids. 

Sugar. 

Per  cent. 

Per  cent. 

4.00 

4.00 

0.50 

0.50 

1.00 

4.50 

Total 1.50  1.50  5.00 

In  a  recent  publication  254  Thompson  S.  Westcott  presents 
new  formulae  for  the  preparation  of  whey,  cream,  and  whole 
milk  mixtures.  In  the  newer  method  the  proportions  of  casein 
and  lactalbumin  can  be  altered  at  will.  He  has  adopted  Van 
Slyke's  figures  of  four  to  one  for  the  proportion  of  caseinogen 
to  lactalbumin  {Journal  of  the  American  Chemical  Society, 
November,  1893,  p.  605);  lactalbumin  therefore  equals  one- 
quarter  casein.  Westcott  estimates  on  the  basis  of  one  per 
cent,  whey-proteids  in  whey  (Wisconsin  Agricultural  Experi- 
ment Station).  The  significance  of  the  symbols  used  in  the 
formulae  is  as  follows: 


308  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

F  =  desired  fat  percentage 

K  =  desired  casein  percentage 

A  =  desired  lactalbumin  percentage 

S  =  desired  sugar  percentage 

W  =  desired  diluent 

C  =  quantity  of  cream  in  ounces 

M  =  quantity  of  milk  in  ounces 

Wh  =  quantity  of  whey  in  ounces 

L  =  quantity  of  dry  lactose  in  ounces 

Q  ==  total  quantity  of  mixture 

P/  =  percentage  of  combined  proteids  supplied  by  milk  and  cream 

A'  =  percentage  of  lactalbumin  supplied  by  whey 

Therefore,  F  =  K  +  |K 

and  A/  =  A-|K 

Having  found  the  value  of  A',  the  quantity  of  whey  is  easily  calculated 
by  the  proportion : 

A'  :  1.00  :  :  Wh  :  Q 

Whence  Wh  =  —  X  Q  or  Wh  =  A/VQ 

1.00 

Example. — Kequired  a  mixture  of  forty  ounces  containing 
fat  three  per  cent.,  casein  0.80  per  cent.,  lactalbumin  0.50  per 
cent.,  sugar  six  per  cent,  (sixteen  per  cent,  cream  to  be  used). 

p/     =.80 +.20  =  1.00 
A'     =.50— .20=    .30 
.  \  Wh  =  .30  X  40  =  12  ounces 

By  substituting  in  his  regular  formula  (page  302)  the  value  of  P' 
instead  of  P,  we  obtain  : 

C    =  (8-60 -LOO)  40     =    8ounces 
12.4 


and 


M=8.60X<O_4X8=   3ounces 
4 

W  =  40  —  (8  +  3  +  12)  =  17  ounces 


HOME   MODIFICATION   OF   MILK.  309 

The  amount  of  lactose  is  determined  by  the  formula : 
L_QXS-(4C  +  4.4M  +  4.8  Wh) 
100 
,h  =  40X6-(4X8+_4.4X3  +  4.jXi2)  =  lf  ounceg 
100  8 

Ordinarily,  sixteen  per  cent,  cream  will  furnish  sufficient 
fat;  rarely  twenty  per  cent,  cream  will  be  needed.  The  pro- 
portion of  lactalbumin  can  never  exceed  one  per  cent,  and  will 
practically  always  fall  below  this.  The  range  of  variation  of 
the  casein,  lactalbumin,  and  fat  has  been  calculated  for  dif- 
ferent strengths  of  cream.  In  the  main  they  may  be  stated  as 
follows :  from  one  to  four  per  cent,  fat,  from  0.07  to  3.20  per 
cent,  casein,  and  from  0.017  to  0.95  per  cent,  lactalbumin. 

Conversely,  to  determine  the  proportions  of  fat,  casein,  and 
lactalbumin  in  a  given  mixture,  we  may  use  the  following : 

For  fat  percentage : 

C 

—  X  (16  or  20  or  32)  =  fat  percentage  from  cream 

Q 
M 

—  X  4  =  fat  percentage  from  milk 

Sum  of  these  =  fat  percentage  in  the  modification 

For  caseinogen  percentage : 

—  X  (3.6  or  3.2  or  2.8)  X  -  =  caseinogen  percentage  from  cream 
Q  5 

M  4 

—  X  4  X  -  =  caseinogen  percentage  from  milk 

Q 5 

Sum  of  these  =  caseinogen  percentage  in  the  modification 

For  lactalbumin  percentage : 

C  1 

X  (3.6  or  3.2  or  2.8)  X  -  =  lactalbumin  percentage  from  cream 

Q  o 

M  1 

X  4  X  =  lactalbumin  percentage  from  milk 

Q  5 
Wh 
XI  =  lactalbumin  percentage  from  whey 

Sum  of  these  =  lactalbumin  percentage  in  modification 

s  =  100  L  +  4  C  -f-  4.4  M  -f  4.8  Wh 

Q 

Note. — Westcott  includes  all  the  "  whey-proteids"  under  the  heading 
"lactalbumin." 


310 


THE   ARTIFICIAL   FEEDING   OF   INFANTS. 


Top-Milk  Mixtures. 

Chapin's  method  was  described  in  the  New  York  Medical 
Journal,  February  23,  1901,  and  may  be  summarized  as  fol- 
lows: 

The  results  of  a  large  number  of  analyses  of  top  milk  by 
the  Babeock  method  enable  us  to  divide  milk  into  three  classes, 
the  poor,  the  medium,  and  the  rich,  in  which  the  percentages 
of  fat  average  three,  four,  and  five  respectively.  When  bottled 
milk  is  allowed  to  stand  undisturbed,  most  of  the  cream  will 
rise  within  from  sixteen  to  twenty  hours;  the  fat  in  the 
skimmed  milk  will  vary  from  0.5  to  1.5  per  cent. 

Chapin's  table  represents  the  varying  percentages  of  fat  in 
the  upper  sixteen  ounces  of  a  quart  bottle  of  milk  which  has 
stood  for  at  least  twelve  hours. 


Fat 

in  whole  milk 

3  per  cent. 

4  per  cent. 

5  per  cent. 

Fat 

in  skimmed  milk  .  . . 

0.5 

1.0  1.5 

0.5 

1.0 

1.5 

0.5 

1.0     1.5 

Fat 

in  top  six  ounces. .  .  . 

13.8 

11.6  9.5 

19.1 

17.0 

14.8 

24.5 

22.3  20.1 

Fat 

in  top  seven  ounces  . 

11.9 

10.1  8.3 

16.5 

14.7 

12.9 

21.0 

19.4  17.5 

Fat 

in  top  eight  ounces. . 

10.5 

9.0  7.5 

14.5 

13.0 

11.5 

18.5 

17.0  15.5 

Fat 

in  top  nine  ounces  . . 

9.5 

8.1  6.8 

12.9 

11.7 

10.4 

16.5 

15.2  14.0 

Fat 

in  top  ten  ounces  . . . 

8.6 

7.4  6.3 

11.7 

10.6 

9.5 

14.9 

13.8  12.7 

Fat 

in  top  eleven  ounces . 

7.8 

6.8  5.9 

10.7 

9.7 

8.8 

13.6 

12.6  11.7 

Fat 

in  top  twelve  ounces. 

7.2 

6.3  5.5 

9.8 

9.0 

8.1 

12.5 

11.7  10.8 

Fat 

in  top  thirteen  ounce 

s     0.7 

6.0  5.2 

9.1 

8.4 

7.6 

11.6 

10.8  10.1 

Fat 

in  top  fourteen  ounce 

;      6.3 

5.6  5.0 

8.5 

7.8 

7.2 

10.7 

10.1     9.5 

Fat 

in  top  fifteen  ounces. 

5.9 

5.3  4.7 

8.0 

7.4 

6.8 

10.1 

9.5     9.0 

Fat 

in  top  sixteen  ounces. 

5.5 

5.0  4.5 

7.5 

7.0 

6.5 

9.5 

9.0     8.5 

If  Chapin's  method  is  to  be  used,  and  it  is  impossible  to 
obtain  analyses  of  the  fat  in  the  whole  milk  and  skimmed  milk, 
the  physician  must  be  content  with  approximate  percentages: 
accuracy  is  out  of  the  question.  The  market  milk  furnished 
by  the  smaller  dealers  to  the  poorer  classes  probably  rarely 


HOME   MODIFICATION   CTF  ^&r-        . 3H 

exceeds  the  legal  limit  of  three  per  cent.  fat.  The  milk  from 
the  better  class  of  dairies  will  contain  as  much  as  four  per 
cent,  fat  or  even  higher.  The  high-grade  product  of  Alderney 
and  Jersey  cattle  will  often  equal  four  and  a  half  or  five  per 
cent. 

Assuming  then,  for  example,  that  we  can  obtain  a  medium 
milk,  and  taking  the  middle  column  of  Chapin's  medium  milk 
table  as  the  safest  average,  we  then  divide  this  figure  by  the 
degree  of  dilution  employed  in  order  to  obtain  the  percentage 
of  fat  in  our  mixture.  We  assume,  for  facility  in  calculation, 
that  the  percentages  of  proteids  and  sugar  in  our  cream  are 
four  each  (actually  they  are  somewhat  lower  in  cream  of  high 
fat  percentage).  For  instance,  the  upper  nine  ounces  of  me- 
dium milk  (middle  column)  contain  11.7  per  cent,  fat,  four 
per  cent,  sugar,  and  four  per  cent,  proteids.  To  prepare  thirty- 
six  ounces  for  the  day's  supply  we  add  to  these  nine  ounces 
twenty-seven  ounces  of  a  five  per  cent,  sugar  solution,  thus 
diluting  the  top  milk  four  times ;  dividing  by  four,  we  get  this 
result:  fat  2.92  per  cent.,  proteids  one  per  cent.,  and  sugar 
one  per  cent,  plus  five  per  cent,  (in  the  diluent)  equals  six 
per  cent.  If  we  mix  the  upper  ten  ounces  of  medium  milk 
(middle  column)  with  twenty  ounces  of  a  five  per  cent,  sugar 
solution,  and  divide  the  percentages  by  three,  our  mixture  will 
contain:  fat  3.53  per  cent.,  proteids  1.33  per  cent.,  and  sugar 
1.33  per  cent,  plus  five  per  cent,  (in  the  diluent)  equals  6.33 
per  cent. 

To  make  four  per  cent,  sugar  solution  add  one  ounce  of  lac- 
tose to  twenty-five  ounces  of  water;  to  make  five  per  cent, 
sugar  solution  add  one  ounce  of  lactose  to  twenty  ounces  of 
water;  to  make  six  per  cent,  sugar  solution  add  one  ounce  of 
lactose  to  sixteen  and  two-thirds  ounces  of  water. 

Chapin  has  devised  a  dipper  of  one  ounce  capacity  which  can 
easily  be  inserted  into  the  neck  of  the  ordinary  quart  milk- 
bottle.  The  obvious  advantages  of  this  method  are  that  the 
consumer  obtains  a  product  in  which  the  dangers  of  contamina- 


312  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

tion  from  handling  are  reduced  to  a  minimum,  that  the  neces- 
sity for  employing  commercial  cream  is  avoided,  and  that  the 
cream  and  milk  in  our  mixture  are  obtained  from  the  same 
source. 

In  order  to  test  more  fully  the  range  of  variations  of  the 
fat  in  top  milk,  the  authors  decided  to  obtain  a  number  of 
analyses  of  the  product  of  a  single  first-class  dairy. 

It  seemed  reasonable  to  suppose  that  the  variations  would 
be  less  than  those  found  in  Chapin's  experiments  with  milk 
from  different  sources.  The  results,  however,  showed  that  in 
a  whole  milk  with  a  fat  percentage  varying  from  five  to  5.5 
the  amounts  of  fat  in  the  upper  ounces  showed  in  many  in- 
stances as  great  or  greater  variations  than  Chapin's  figures 
indicate.  Without  daily  tests  absolute  accuracy  is  therefore 
impossible  with  top-milk  mixtures. 

When  we  consider,  however,  the  frequent  and  decided  varia- 
tions in  the  fat  content  which  occur  in  mother's  milk  without 
harm  to  the  healthy  infant,  it  seems  probable  that  moderate 
variations  in  the  fat  content  in  a  cow's  milk  mixture,  when 
the  child  has  become  accustomed  to  the  digestion  of  cow's  milk, 
will  probably  rarely  lead  to  digestive  disturbances,  provided 
the  milk  is  pure  and  the  child  is  carefully  fed. 

The  tests  we  have  made  fairly  establish  a  working  average 
for  the  milk  of  one  dairy  during  a  certain  period  (from  Janu- 
ary to  March).  We  hope  to  continue  them  during  the  re- 
mainder of  the  year,  and  also  to  establish  a  ratio  between  the 
fat  in  the  whole  milk  and  the  fat  in  the  top  milk  in  the  same 
bottle.  When  this  ratio  has  been  determined,  an  occasional 
test  of  the  whole  milk  will  show  whether  the  proper  propor- 
tion of  fat  is  being  maintained. 

The  tests  were  made  for  us  by  Mr.  Walter  Cuthbert,  a  grad- 
uate in  chemistr}-,  whom  we  were  fortunate  enough  to  interest 
in  this  subject.  He  controls  in  large  part  the  output  of  the 
Spotswood  Dairy  Farm  at  Broad  Axe,  Pennsylvania. 

The  whole-milk  tests  show  a  uniformly  high  percentage  of 


HOME   MODIFICATION    OF   MILK.  313 

fat;  the  uppermost  ounces  from  such  a  milk  are  therefore  not 
available  for  infant  feeding,  as  any  reasonable  dilution  of  the 
fat  would  bring  the  proteid  percentage  much  below  what  is 
needed.  This  difficulty  could  be  obviated  by  dilution  with 
skimmed  milk  or  whole  milk,  using  the  top  milk  only  as  a 
rich  cream.  As  one  of  the  primary  objects  of  the  top-milk 
method  is  to  obtain  the  fat  and  proteids  from  the  same  supply, 
it  is  better  to  remove  the  upper  ten  ounces  or  more  even  if  this 
entire  amount  is  not  needed.  The  larger  amounts  will  also 
contain  practically  all  the  fat  from  that  quart,  and  the  varia- 
tions will  depend  on  the  amount  of  fat  in  the  whole  milk,  while 
the  proportion  of  this  ingredient  in  the  upper  two  to  six  ounces 
depends  also  on  the  length  of  time  the  cream  has  been  raising, 
the  temperature,  physical  condition  of  the  fat-globules,  etc. 
For  these  reasons  our  tests  have  mainly  been  made  with  the 
larger  amounts  of  top  milk. 

In  making  the  fat  tests  Mr.  Cuthbert  employed  the  Leff- 
mann-Beam  method  described  on  page  342.  The  quart  bottles 
were  selected  entirely  by  chance.  The  cream  had  been  raising 
from  fourteen  to  sixteen  hours  and  the  cream  layer  was  there- 
fore fully  formed. 

In  removing  the  top  milk  we  employed  a  cone-shaped  dipper 
constructed  according  to  J.  C.  Gittings's  design  by  V.  Clad  & 
Sons.  The  cone-shaped  base  permits  the  dipper  to  pass  easily 
through  the  cream  layer  without  disturbing  it. 


The  first  ounce  was  partially  removed  by  pouring  into  the 
dipper,  which  could  then  be  inserted  without  causing  the  cream 
to  overflow.  It  was  a  noticeable  fact  that  the  actual  measure- 
ment of  the  cream  layer  in  all  the  bottles  tested  varied  only 
from  3.4  to  four  inches.     The  depth  of  this  layer  depends  on 


314 


THE   ARTIFICIAL   FEEDING   OF   INFANTS. 


the  shape  of  the  bottle,  the  length  of  time  the  cream  has  been 
raising,  and  the  temperature.  The  first  two  conditions  being 
the  same  in  all  our  tests,  we  found  the  following  variations 
dependent  on  the  weather  conditions,  irrespective  of  the  fact 
that  the  milk  was  kept  well  iced. 

«r    ii,        „   j-i-„  Inches  of  cream  in  one 

Weather  conditions.  quart  JJJ^ 

Moderate  and  warm 3. 70  average 

Moderate  and  freezing 3.75  to  4.00 

Continuous  freezing 4.00  average 


Table  op  Fat  Percentages  in   Top  Milk. 


Whole 

Upper  six- 

Fourteen 

Twelve 

Ten 

Eight 

Six 

Four 

milk. 

teen  ounces. 

ounces. 

ounces. 

ounces. 

ounces. 

ounces. 

junces. 

5.0 

9.6 

10.2 

12.3 

14.4 

18.6 

21.6 

23.4 

5.0 

9.6 

10.5 

12.6 

14.4 

18.9 

21.6 

23.7 

5.0 

9.6 

10.8 

13.2 

14.4 

19.2 

22.5 

24.3 

5.1 

9.6 

10.8 

13.2 

15.0 

19.8 

22.8 

24.3 

5.1 

9.6 

10.8 

13.2 

15.0 

19.8 

5.1 

9.9 

11.4 

13.5 

15.0 

20.1 

5.2 

10.2 

11.4 

13.5 

15.6 

5.2 

10.2 

11.7 

13.5 

15.6 

5.2 

10.2 

11.7 

13.6 

15.6 

5.3 

10.2 

11.7 

13.8 

15.9 

5.3 

10.4 

11.8 

13.8 

16.2 

5.3 

10.5 

12.0 

13.8 

16.2 

5.4 

10.5 

12.0 

13.8 

16.2 

5.4 

10.8 

12.0 

13.8 

16.8 

5.4 

10.8 

12.0 

14.1 

17.1 

5.4 

13.2 

5.5 

13.2 

Average. 

Average. 

Average. 

Average. 

Average. 

Average.      A 

verage.      A 

verage. 

5.23 

10.11 

11.6 

13.44 

15.56 

19.40 

22.12 

23.92 

HOME   MODIFICATION   OF   MILK.  315 

As  we  will  have  to  dilute  the  top  milk  at  least  three  times, 
the  possible  error  in  the  fat  percentage  of  our  mixture,  ac- 
cording to  this  table,  will  be  reduced  by  this  dilution  so  as 
to  fall  below  0.5, — rarely  as  high  as  this.  For  example,  the 
column  of  fat  values  for  the  upper  fourteen  ounces  shows  the 
greatest  variations, — from  10.2  to  13.2.  If  we  divide  the  aver- 
age of  this  column  (11.6)  by  3  we  get  3.9  fat.  The  possible 
error  will  therefore  be:  10.2-*- 3  =  3.4  and  13.2  -4-  3  =  4.4, 
figures  respectively  .5  above  and  .5  below  the  average.  Although 
this  is  far  from  strict  accuracy,  it  is  probably  less  of  an  objec- 
tion than  might  be  supposed. 

Condensed  Milk. 

No  preparation  of  cow's  milk  enjoys  a  wider  popularity 
among  the  laity,  especially  among  the  poorer  classes,  than  con- 
densed milk.  Few  physicians  of  wide  experience  have  failed 
to  note  that  many  infants  have  not  only  lived  but  thrived  upon 
an  exclusive  diet  of  condensed  milk  during  the  early  months 
of  life.  Condensed  milk  must  be  well  diluted  before  it  is  given 
to  the  infant.  If  we  add  to  it  from  eight  to  twelve  times  its 
amount  of  water,  we  reduce  its  proteid  and  fat  content  to  one 
per  cent,  and  less,  while  the  proportion  of  sugar  becomes  from 
five  to  six  per  cent.  This  amount  of  sugar  is  sufficient,  but  the 
proportion  of  proteids  and  fat  is  too  low,  especially  the  latter. 

One  possible  explanation  for  the  child's  apparent  thriving 
and  gain  in  weight  is  that  a  "  teaspoonf ul"  of  the  condensed 
milk  is  in  reality  almost  two  teaspoonfuls,  since  almost  as  much 
of  the  thick  syrupy  milk  adheres  to  the  bottom  and  edges  of  the 
spoon  as  the  spoon  contains.  We  actually,  then,  administer 
an  excess  of  sugar,  a  proper  proportion  of  proteids,  and  a 
deficient  amount  of  fat;  the  sugar  can  be  converted  into  fat 
and  give  the  child  its  plump  appearance ;  the  proteids  are  pre- 
sented in  an  easily  digestible  form,  since  they  clot  in  much 
finer  curds  than  raw  cow's  milk;  while  the  fat,  being  in  fine 
emulsion,  is  also  usually  well  utilized.     Clinical  observation 


316  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

has  proved,  however,  that  a  prolonged  exclusive  diet  of  con- 
densed milk  often  results  in  the  development  of  such  nutri- 
tional disorders  as  anaemia,  rickets,  scurvy,  and  athrepsia. 
Moreover,  the  infant,  while  apparently  healthy,  lacks  vital 
resistance  and  easily  succumbs  to  the  various  infectious  diseases 
which  he  may  contract.  The  deficiency  in  fat,  the  excess  of 
sugar,  and  the  "lack  of  freshness"  in  condensed  milk  are 
probably  all  causative  factors  in  these  results. 

There  is  no  doubt  that  the  judicious  employment  of  con- 
densed milk  meets  certain  indications  in  infant  feeding, — 
namely,  where  persistent,  intelligent  modifications  of  cow's 
milk  have  failed,  and  where  lack  of  resources  or  of  intelligent 
co-operation  on  the  part  of  the  mother  prevents  the  adoption  of 
more  elaborate  methods  of  feeding.  As  a  temporary  expedient, 
condensed  milk  may  be  administered  for  short  periods  of  time 
to  tide  over  emergencies,  especially  among  the  poor  during  the 
summer  months,  when  it  is  difficult  to  obtain  good  milk  and  to 
keep  it  from  spoiling. 

Whenever  possible,  we  should  attempt  to  supplement  the 
inherent  deficiencies  in  a  condensed  milk  diet  by  the  addition 
of  fresh  cream.  With  such  supplement  the  infant  undoubtedly 
will  receive  sufficient  nourishment  to  meet  the  demands  of  the 
organism,  even  for  long  periods  of  time,  though  it  should  always 
be  our  aim  to  revert  to  a  diet  of  cow's  milk  as  soon  as  oppor- 
tunity offers.  It  is  important  to  select  those  brands  of  con- 
densed milk  which  contain  high  fat  percentages  (some  as  high 
as  twelve  per  cent.)  and  to  use  only  those  which  are  preserved 
by  the  addition  of  cane-sugar.  The  following  formulae,  based 
on  Holt's  analysis  of  Eagle  Brand  Condensed  Milk,  are  given 
as  examples  of  what  percentages  may  be  obtained  with  mixtures 
of  condensed  milk  and  cream. 

When  we  desire  to  increase  the  proteid  percentage  without 
appreciably  increasing  the  fat,  we  can  use  whey  to  replace  a 
portion  of  the  water  in  the  diluent,  taking  care  not  to  increase 
the  sugar  excessively. 


HOME   MODIFICATION    OF   MILK. 


317 


Proteids 
Per  cent 

Fat. 
Per  cent. 

Sugar. 
Per  cent. 

Salts. 
Per  cent. 

I. 

Cream  (twelve  per  cent.)  one  part.     3.8 

12.00 

4.2 

0.64 

Condensed  milk  one  part 8.4 

7.00 

50.00 

1.39 

Water  six  parts 

8  )  12.2 

19.00 

54.2 

2.03 

Average 1.5 

2.5 

6.75 

0.25 
Per  cent. 

II. 

Cream  (sixteen  per  cent.)  one  part. 

Condensed  milk  one  part 

Water  six  parts 

■  =  ■ 

'  Proteids 
Fat 

Sugar. . 
L  Salts... 

1.5 
3.00 
6.75 
0.25 

III. 

Cream  (sixteen  per  cent.)  one  part. 

Condensed  milk  one  part 

Water  ten  parts 

•  =  • 

Proteids 
Fat 

Sugar  . 
.  Salts... 

1.00 
2.00 
4.5 
0.16 

By  employing  cream  of  higher  fat  percentage  the  proportion 
of  fat  can  be  increased,  and  by  using  cream  of  lower  fat  per- 
centage the  proportion  of  proteids  can  be  increased. 

Much  less  can  be  said  in  favor  of  the  other  artificial  prepa- 
rations of  milk,  such  as  the  proprietary  foods.  Some  of  these 
are  designed  to  be  used  with  fresh  cow's  milk,  and  furnish  a 
convenient  means  of  beginning  the  administration  of  starch 
towards  the  end  of  the  first  year.  In  making  a  selection,  prefer- 
ence should  be  given  to  those  preparations  in  which  the  starch 
has  been  completely  dextrinized. 

Another  class  of  proprietary  foods  are  widely  advertised  as 
perfect  substitutes  for  mother's  milk  when  simply  diluted  with 
water.  Many  of  them  contain  a  large  amount  of  starch  in  an 
insoluble  form,  while  the  casein  and  fat  in  dried  form  differ 
widely  from  the  same  ingredients  in  cow's  milk.  This  class  of 
foods  should  never  be  employed  to  the  exclusion  of  cow's  milk, 
except  as  a  temporary  expedient. 


CHAPTEK   XIV. 

PRACTICAL    RULES   FOR   FEEDING. 

One  of  the  practical  objections  to  the  home  modification  of 
milk  for  infant  feeding  has  been  the  length  of  time  necessary 
to  fully  explain  the  process  to  the  mother  or  nurse,  time  which 
few  busy  practitioners  have  to  spare.  The  best  way  to  obviate 
this  difficulty  is  to  have  a  printed  list  of  directions  to  present 
to  the  mother.  We  have  attempted  to  prepare  such  a  list, 
which  may  be  used  or  modified  as  the  physician  may  desire. 
When  the  principles  of  cleanliness  are  once  understood,  the 
mother  can  easily  apply  them  to  any  method  of  feeding,  such 
as  whey-cream  mixtures,  top-milk  mixtures,  etc. 

I.  The  milk  should  be  obtained  in  bottles  which  have  been 
filled  and  sealed  at  the  dairy. 

II.  As  soon  as  the  bottle  is  received  it  should  be  placed  on 
ice  until  the  day's  food  is  to  be  prepared. 

III.  All  utensils  which  are  to  be  employed  in  the  milk- 
modification  should  be  cleansed  with  boiling  water,  if  possible, 
just  before  being  used. 

IV.  The  following  articles  are  necessary:  (a)  A  jar  of 
boiled  water  or  freshly  prepared  barley-water,  (b)  A  jar 
containing  milk-sugar  or  granulated  sugar,  (c)  A  bowl  con- 
taining freshly  boiled  water,  in  which  stand  a  tablespoon,  a 
knife,  and  a  one-ounce  dipper  (for  top-milk  mixtures),  (d) 
A  freshly  scalded  eight-ounce  glass  graduate,  (e)  Two  freshly 
scalded  quart  preserving  jars  and  caps,  (f)  A  bottle  of  lime- 
water,     (g)  An  enamelled  or  glass  funnel,  freshly  scalded. 

V.  When  the  mixture  is  to  be  prepared,  the  mother  or 
nurse  should  thoroughly  wash  her  hands  before  placing  these 
articles  upon  a  clean  napkin.    The  neck  and  cap  of  the  bottle 

318 


PRACTICAL   RULES   FOR   FEEDING.  319 

of  milk  (or  cream)  are  next  thoroughly  cleansed  with  hot 
water.  The  pasteboard  cap  is  then  removed  by  inserting  the 
knife  under  the  edge.  The  upper  half-inch  of  milk  or  cream 
may  be  removed  with  a  spoon  and  discarded  if  the  cap  has  been 
carelessly  adjusted. 

VI.  Eemove  the  upper  ounces  of  top  milk  from  the 

jar  of  milk  with  the  dipper  (gently  pouring  the  first  half- 
dipperful  to  allow  space  for  the  dipper  to  be  inserted),  or 

measure ounces  of  cream  and ounces  of  whole  milk 

(or  skimmed  milk)  in  the  glass  graduate.  The  milk  and 
cream  (or  top  milk),  as  they  are  measured,  should  be  poured 
into  one  of  the  freshly  scalded  quart  jars  (No.  I.). 

VII.  Dissolve  ounces  of  milk-sugar    (or  granulated 

sugar)   in  ounces  of  boiling  water   (in  the  graduate). 

Pour  this  at  once  into  jar  No.  II.  and  add  ounces  of 

boiled  water    (or  barley-water) ;    ounces  of  lime-water 

(if  desired)  are  then  added.  The  contents  of  jar  No.  I.  are 
then  poured  into  jar  No.  II.  and  thoroughly  mixed.  It  is 
then  tightly  capped  and  placed  on  ice  until  ready  for  use. 

N.B. — It  is  important  to  remember  that  any  fluid  used  in  the 
milk  mixtures  other  than  milk  and  cream  is  a  diluent.  The 
simplest  method  is  to  dilute  milk  and  cream  with  water. 
Whatever  diluents  are  added  to  our  mixture,  such  as  whey, 
barley-water,  sugar  solution,  lime-water,  etc.,  the  total  quan- 
tity of  such  diluents  must  be  made  to  equal  the  total  amount  of 
diluent  required.  The  sugar  solution  may  be  made  with  either 
plain  water  or  barley-water.  Holt  recommends  that  the  sugar 
of  milk  should  be  dissolved  in  boiling  water.  The  amount  of 
the  latter  should  then  be  subtracted  from  the  total  amount  of 
the  solution. 

VIII.  When  the  infant  is  to  be  fed  the  jar  is  again  agitated 
and  the  proper  quantity  poured  into  a  freshly  scalded  feeding- 
bottle   through   a   freshly   scalded   funnel;    the   nipple,   also 


320  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

freshly  scalded,  is  then  put  on  and  the  bottle  stood  in  hot 
water  until  the  milk  feels  warm  to  the  back  of  the  hand.  Ex- 
ceptionally, or  in  summer,  the  child  prefers  it  cool.  In  cases  of 
extreme  gastric  irritability  it  may  be  better  tolerated  ice- 
cold. 

IX.  Feeding-bottles  should  be  cleansed  with  cold  water  as 
soon  as  the  child  has  finished  its  meal,  and  kept  filled  with 
•water  until  ready  to  be  scalded  for  use.     The  bottles  should 

have  rounded  corners  so  that  they  may  be  easy  to  clean. 

X.  The  rubber  nipples  should  be  thoroughly  cleansed  on 
both  surfaces  with  soap  and  cold  water  and  kept  in  a  cup  of 
borax  solution  until  ready  to  be  scalded  for  use. 

XL  The  baby  should  be  fed : 

During    the    first    month    every    hours    from    

a.m.  to  p.m.,  with  night  feedings.     ounces 

should  be  given  at  each  feeding. 

During  the  second  and  third  months  give ounces  every 

hours  from a.m.  to p.m.,  with night  feed- 
ings. 

During  the  fourth  and  fifth  months  give ounces  every 

hours  from a.m.  to p.m.,  with night  feed- 
ings. 

From  the  sixth  to  the  eighth  month  give ounces  every 

hours  from a.m.  to p.m.     No  night  feedings. 

From  the  ninth  to  the  twelfth  month  give ounces  every 

hours  from a.m.  to p.m. 

XII.  The  infant  should  be  held  in  a  reclining  position  to 
be  fed,  and  should  consume  the  whole  amount  in  from  fifteen 
to  twenty  minutes.  Where  there  is  difficulty  in  breathing,  the 
time  for  the  meal  may  be  lengthened.  Should  the  infant  re- 
fuse the  bottle  before  the  entire  quantity  is  consumed,  after 
a  short  interval  offer  the  bottle  again.  If  it  is  again  refused, 
the  remainder  of  the  milk  should  be  thrown  away  and  the 
infant  should  not  be  fed  again  until  the  proper  interval  has 
elapsed. 


PRACTICAL   RULES   FOR   FEEDING.  321 

The  practice  of  some  mothers  and  nurses  of  moistening  the 
nipple  beforehand  or  putting  it  in  the  mouth  to  test  the  tem- 
perature of  the  milk  cannot  be  too  strongly  condemned. 

Whenever  possible,  it  is  preferable  to  have  separate  feeding- 
bottles.  After  the  total  quantity  for  the  day  has  been  mixed 
and  well  shaken  the  bottles  are  to  be  filled  through  the  scalded 
funnel  and  stoppered  with  sterile  non-absorbent  cotton.  These 
cotton  plugs  should  be  made  of  sufficient  size  to  tightly  stop- 
per the  feeding-bottles.  The  plugs  may  be  sterilized  by 
steaming  them  for  three  hours  in  a  double  boiler  (such  as  is 
used  in  most  households  for  cooking  cereals).  It  is  more  con- 
venient to  prepare  a  large  quantity  of  these  plugs  at  a  time  and 
to  keep  them  in  a  scalded  fruit  jar,  tightly  capped.  They  will 
then  remain  approximately  sterile.  The  stoppered  feeding- 
bottles  must  be  kept  on  ice  and  warmed  when  needed,  the  plug 
being  then  exchanged  for  a  freshly  scalded  nipple. 

If  top  milk  is  to  be  used,  the  physician  should  ascertain 
when  the  milk  was  bottled,  so  that  the  necessary  time  for  the 
raising  of  the  cream  may  be  allowed.  The  milkman  should 
be  requested  to  avoid  any  agitation  of  the  bottles  which  would 
interfere  with  the  raising  of  the  cream.  During  warm  weather 
the  milk  should  be  delivered  only  after  some  one  is  about 
to  receive  it  and  place  it  at  once  on  ice.  An  hour's  stand- 
ing on  the  doorstep  in  summer  may  render  the  milk  unfit  for 
use. 

The  table  which  follows  is  intended  to  indicate  the  average 
amounts  of  the  milk  mixture  to  be  given  at  each  feeding  and 
the  intervals  between  meals.  Since  these  are  influenced  by  a 
variety  of  factors,  such  as  the  condition  of  the  digestion,  the 
gain  in  length  and  weight,  etc.,  the  table  must  be  considered 
to  represent  only  a  normal  average.  It  is  rarely  advisable  to 
furnish  the  mother  or  nurse  a  list  of  directions  covering  ex- 
tensive periods  of  time,  since  they  are  only  too  apt  to  rely  on 
them  and  to  ignore  evidences  of  indigestion,  failure  to  gain  in 
weight,  etc.,  which  require  the  physician's  personal  attention. 
21 


322  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 


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PRACTICAL   RULES   FOR   FEEDING.  323 

It  is  always  best  to  adhere  as  closely  as  possible  to  a  given 
routine  in  regulating  the  intervals  between  meals.  This  ap- 
plies to  the  healthy  as  well  as  to  the  sick  infant.  There  is  less 
clanger  of  the  interval  being  too  long  than  too  short;  if  the 
child  is  sleeping  at  the  time  for  his  feeding,  it  is  best  not  to 
disturb  him.  The  succeeding  meals  should  be  given  at  the 
proper  intervals,  even  if  not  on  schedule  time. 

It  may  be  found  that  the  infant  will  habitually  oversleep; 
if  he  is  healthy  and  gaining  weight  the  longer  interval  may 
safely  be  allowed.  Occasionally  the  infant  will  turn  night  into 
day  by  persistently  oversleeping  during  the  daytime  and  will 
want  his  food  frequently  at  night.  It  is  then  necessary  to 
waken  him  at  proper  intervals  during  the  day  and  thus  break 
up  the  habit. 

If  an  infant  is  born  underweight  and  shows  early  evidences 
of  indigestion,  it  may  be  necessary  to  adhere  to  the  two-hour 
intervals  and  to  weaker  dilutions  for  several  months.  These 
cases  cannot  be  considered  normal,  since  the  capacity  of  the 
stomach  and  the  nutritional  demands  of  the  organism  are 
usually  less  than  those  of  the  average  child.  They  must  be 
studied  with  especial  care,  and  no  absolute  rules  can  be  laid 
down  for  their  management. 

Much  oftener  we  encounter  the  difficulty  of  a  too  frequent 
desire  for  food.  The  conditions  which  render  it  advisable  to 
increase  the  strength  or  the  quantity  of  our  milk  mixture  are: 
when  the  infant  habitually  cries  after  finishing  his  meal  and 
continues  to  cry  until  the  next  feeding,  when  there  are  no 
signs  of  indigestion,  and  when  it  is  impossible  to  find  any  other 
cause  for  his  fretfulness.  The  change  in  the  diet  is  particu- 
larly indicated  when  there  is  failure  to  gain  in  weight  or  the 
gain  is  persistently  below  normal.  Habitual  crying,  however, 
is  usually  a  sign  of  colic  and  indigestion  and  requires  read- 
justment of  the  diet.  Nearly  all  these  cases  show  evidences 
of  malnutrition,  and  their  cry  not  only  denotes  pain,  but  also 
craving  for  a  food  which  will  satisfy  the  needs  of  their  system. 


324  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

The  principal  difficulty  in  the  management  of  these  cases  is 
the  enforcement  of  sufficiently  long  intervals  between  meals. 
This  should  rarely  be  less  than  two  hours;  often  a  longer 
interval  may  be  observed  with  advantage.  A  drink  of  plain 
water  or  of  barley-water  between  meals  will  do  no  harm  and 
will  often  suffice  to  quiet  the  child.  When  we  are  forced  to 
feed  the  child  on  a  milk  mixture  containing  very  low  propor- 
tions of  proteids  and  fat,  which  are  insufficient  for  proper 
nutrition  and  growth,  it  is  often  desirable  to  supplement  the 
diet  with  one  of  the  predigested  foods,  such  as  liquid  pepto- 
noids,  panopepton,  or  predigested  beef.  Somatose  and  plasmon 
may  also  be  used,  but  are  not  always  well  tolerated.  These 
preparations  can  be  given  either  with  the  meal  or  during  the 
interval. 

In  an  entirely  distinct  class  are  those  infants  who  are 
particularly  robust  from  birth,  and  whose  weight,  length, 
and  rapidity  of  growth  are  above  the  normal.  The  food  re- 
quirements of  these  cases  may  be  from  a  month  to  six 
weeks  in  advance  of  the  normal  requirements  of  the  average 
infant. 

If  the  infant  vomits  a  few  minutes  after  finishing  his  meal, 
before  curdling  has  occurred,  either  too  much  milk  has  been 
taken  or  it  has  been  consumed  too  quickly.  To  obviate  this 
difficulty  unpierced  nipples  should  be  procured  in  which  the 
aperture  can  be  made  as  small  as  desired,  or  the  device  of  Bon- 
will  14  may  be  resorted  to.  He  inverts  a  small  nipple  into  the 
neck  of  the  bottle;  a  short  nipple  is  then  put  on  in  the  usual 
manner.  The  advantages  of  this  method  are  the  vigorous  suck- 
ing that  it  demands  and  the  length  of  time  required  for  the 
meal.  It  is  obviously  unsuited  for  weak  infants.  When  re- 
gurgitation persists  in  spite  of  these  measures,  it  is  usually 
safer  to  reduce  the  quantity  of  the  food  mixture,  since  the 
amount  is  probably  in  excess  of  the  gastric  capacity;  or  the 
proportion  of  fat  or  proteids  may  be  too  high  (Holt)  and 
need  reduction.    The  propriety  of  pasteurization  or  of  sterili- 


PRACTICAL   RULES   FOR   FEEDING.  325 

zation  has  already  been  discussed  (page  293).  If  one  or  the 
other  is  considered  desirable,  it  should  be  done  as  soon  as  the 
milk  is  received,  and  the  milk  should  then  be  kept  on  ice  until 
the  day's  mixing  is  to  be  done.  If  separate  feeding-bottles 
are  to  be  used,  the  process  may  be  repeated  when  they  are 
filled. 

During  the  heated  term,  when  gastro-intestinal  disorders 
are  particularly  apt  to  occur,  great  care  should  be  exercised 
to  avoid  overtaxing  the  infant's  digestion.  If  the  child  is 
taking  a  milk  mixture  of  high  proportions,  containing  from 
two  to  two  and  a  half  per  cent,  proteids  and  three  and  a  half 
to  four  per  cent,  fat,  it  is  usually  a  good  plan  to  reduce  the 
amount  of  fat  in  our  mixture  and  to  avoid  increasing  the  pro- 
teids. With  the  first  signs  of  gastro-intestinal  disturbance, 
the  proportion  of  both  ingredients  should  be  further  decidedly 
reduced. 

The  necessity  for  the  administration  of  water  to  the  infant 
is  a  point  to  which  attention  has  repeatedly  been  called,  but 
its  importance  is  apt  to  be  overlooked  both  by  the  mother 
and  the  physician.  Water  should  be  administered  between 
feedings,  preferably  about  half  an  hour  before  a  meal;  it 
should  rarely  be  iced  except  during  the  summer  months.  The 
quantity  to  be  given  will  depend  on  the  infant's  individual 
taste. 

Holt.183  When  a  child  has  been  well  started  on  some 
method  of  feeding  and  has  begun  to  gain  regularly  in  weight, 
a  regular  weekly  report  in  writing  may  often  take  the  place  of 
the  physician's  visit.  This  should  include  only  answers  to 
certain  questions, — namely:  1.  Weight:  gain  or  loss  since 
last  report?  2.  Stools:  frequency  and  general  character. 
3.  Vomiting  or  regurgitation:  when  and  how  much?  4. 
Flatulence  or  colic?  5.  Appetite:  is  the  child  satisfied?  Does 
he  leave  any  of  his  food?  6.  Is  he  comfortable  and  good- 
natured?  7.  How  much  does  he  sleep?  8.  Date.  9.  Date  of 
last  report. 


326  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

Method  for  calculating  Milk  Percentage  without  Formula?. 

For  those  who  experience  difficulty  in  estimating  the  strength 
of  a  mixture  of  cream,  milk,  whey,  sugar  solution,  etc.,  in 
proteids,  fat,  sugar,  and  salts,  the  following  table  has  been 
devised.  The  method  of  calculation  is  simple  and  fairly  accu- 
rate. The  first  column  represents  the  number  of  parts  or 
ounces  in  the  total  daily  quantity  of  the  mixture.  The  per- 
centage strength  of  the  different  ingredients  used  must  be 
multiplied  by  the  number  of  parts  used  and  then  divided  by 
the  total  number  of  parts,  in  order  to  ascertain  the  percentage 
strength  of  our  whole  mixture.  An  example  is  given  of  a 
milk,  twelve  per  cent,  cream,  and  seven  per  cent,  sugar  solution 
mixture. 


Parts.         Proteids.  Fats.  Sugar.  Salts. 

Milk 2        2X4    =   8       2X    4=   8    2X4.5=   9       2X0.7   =1.4 

Cream  or  top  milk...        4        4X3.6  =  14.4    4X12  =  48    4X4.2  =  16.8    4X0.64  =  2.56 

Whey 

Sugar  solution 10       10X7  =  70       

Diluent.— Barley-    or 

plain  water 

Lime-water 


Total 16)  22.4  56  95.8  3.96 

Percentage    of     our 
mixture  equals 1.4  3.5  6.0  0.24 


Note. — It  has  been  assumed  that  the  percentage  of  proteids  in  whole 
milk  is  four;  actually  it  will  more  frequently  approximate  3.50.  The 
higher  figure  is  much  more  convenient  for  calculation,  however,  and  can 
lead  to  no  appreciable  error  if  we  recall  that  the  actual  amount  of  proteids 
present  is  from  0.1  to  0.8  lower  than  the  figures  indicate,  according  to  the 
dilution  employed. 


CHAPTER    XV. 


ARTIFICIAL    FOODS. 


According  to  Cautley,3 
as  follows : 


proprietary  foods  may  be  classed 


Group      I.     Foods  prepared  from  cow's  milk. 

(a)  Condensed  milk  without  added  sugar. 

(b)  Condensed  milk  with  added  sugar. 

(c)  Peptonized  milk. 

Group  II.  Foods  prepared  from  cow's  milk  and  modified  cereals ; 
the  starch  unchanged  or  partially  converted  into  dex- 
trin, etc. 

(a)  Containing  much  unchanged  starch, — e.g.,  Nes- 

tle's,  Anglo-Swiss,  etc. 
(6)  The  starch  largely  converted  into  soluble  carbo- 
hydrates, such  as  maltose  and  dextrin, — e.g., 
Allen  and  Hanbury's. 
(c)  Milk  foods  in  which  the  milk  has  been  partially 
peptonized  or  contains  ferments  which  act  on 
the  addition  of  warm  milk,  and  containing 
partially  or  entirely  converted  or  unconverted 
starch, — e.g.,  Benger's  (prepared  with  milk), 
Carnrick's,  Horlick's  Malted  Milk. 

Group  III.     Foods  prepared  from  modified  cereals  only. 

(a)  The  starch  unchanged,—  e.g.,  Robinson's  Pre- 
pared Barley,  Frame's  Food,  Ridge's  Food, 
Neave's  Food. 

(6)  The  starch  partially  changed  by  the  action  of 
malt  diastase, — e.g.,  Savory  and  Moore's 
Food. 

(c)  The  starch  completely  changed, — e.g.,  Mellin's 
Food,  Horlick's  Food. 

327 


328 


THE   ARTIFICIAL   FEEDING   OF   INFANTS. 


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ARTIFICIAL  FOODS.  329 

The  table  on  page  328  is  based  on  Leeds's  analyses.  These 
figures  are  subject  to  marked  variation,  as  may  be  seen  by 
reference  to  the  results  of  other  investigators.  It  may  defi- 
nitely be  accepted  that  the  proportion  of  their  ingredients  is 
not  a  constant  one. 

Monti  "  says  that  Nestle's,  Ridge's,  Mellin's  Food,  etc.,  con- 
tain too  little  fat  and  proteids.  They  are  in  no  sense  a  fit  sub- 
stitute for  mother's  milk,  but  may  be  used  temporarily  with 
good  results.  In  the  first  months  of  life  they  should  not  form 
the  exclusive  nourishment.  When  the  child  is  five  months  old 
and  after  weaning  they  are  useful  adjuvants.  Theinhardt's 
Soluble  Infant  Food  is  similar  to  Mellin's  Food. 

Cautley  38  states  as  an  axiom  that  proprietary  foods  are 
unnecessary  for  the  proper  feeding  of  infants  so  long  as  good 
cow's  milk,  cream,  and  sugar  are  available.  They  should  never 
be  used  before  the  sixth  month,  and  then  only  as  diluents. 

Starr  133  considers  that  proprietary  foods  are  useful  as 
mechanical  attenuants,  but  unless  they  are  prepared  with  milk 
it  is  questionable  whether  any  of  them  can  permanently  meet 
the  demands  of  nutrition. 

Rotch  119  calls  particular  attention  to  the  unreliability  and 
lack  of  uniformity  in  the  composition  of  artificial  foods,  which 
"  vary  too  greatly  in  their  analyses  to  keep  even  within  the 
acknowledged  varying  limits  of  human  milk." 

J.  Lewis  Smith  129  considers  them  useful  only  as  adjuvants. 

Biedert  7  recommends  the  prepared  foods,  added  to  the 
milk  mixture,  after  the  sixth  month  as  a  good  method  of  begin- 
ning the  administration  of  starch.  Bendix  says  that  their  only 
proper  use  is  in  addition  to  other  foods,  for  short  periods  of 
time,  and  never  before  three  months.  Scurvy  may  undoubtedly 
follow  their  prolonged  use. 

Baginsky.5  The  infant  foods  may  be  used  after  the  third 
month  as  an  adjuvant  to  mother's  milk ;  but  the  experience  of 
all  authors  shows  that  the  long-continued  use  of  any  of  them 
causes  a  slight  dyspepsia.    Demme  has  observed  a  diminution 


330  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

in  the  number  of  red  corpuscles  in  children  who  are  fed  too 
early  on  starch. 

Ashby  and  Wright  2  consider  the  artificial  foods  only  useful 
temporarily,  during  a  journey,  etc.,  or  when  milk  will  not  agree 
in  any  form.  They  do  not  readily  ferment,  but  if  used  for 
too  long  a  time,  especially  if  the  children  are  more  than  six 
months  old,  both  rickets  and  scurvy  are  apt  to  ensue. 

Drews  and  Krauss  85  have  found  that  somatose  is  well 
digested  by  healthy  as  well  as  poorly  developed  infants.  It 
produced  a  finer  curd  when  mixed  with  cow's  milk.  Krauss 
found  it  odorless  and  its  taste  not  objectionable.  Small  doses 
seemed  to  increase  peristalsis  without  exciting  the  secretions 
of  the  intestines.  It  was  useful  in  all  disturbances  of  diges- 
tion in  infants,  and  was  especially  valuable  in  replacing  the 
nitrogenous  loss  in  the  organism.  Wolf  156  also  reports  good 
results  with  somatose  in  the  feeding  of  infants;  it  was  well 
borne  in  gastro-intestinal  disorders  and  by  atrophic  infants. 

Condensed  Milk. 

Monti."  There  are  two  principal  varieties  of  condensed 
milk,  one  with  and  the  other  without  sugar.  To  prepare  the 
first,  cow's  milk  with  more  or  less  sugar  added  to  it  is  con- 
densed in  a  vacuum.  It  then  contains  all  the  constituents  in 
an  unaltered  form  if  the  process  is  correctly  carried  out.  Fre- 
quently, on  opening  the  cans,  we  find  the  contents  covered 
with  a  skim  composed  of  crystallized  sugar  and  dried  milk 
materials,  under  which  the  milk  will  keep  for  a  long  time, 
Microscopically,  we  find  fat-droplets  intact  and  numerous  sugar 
crystals.  Fermentation  fungi  are  present  only  when  the  can 
has  been  open  for  some  time.  The  high  sugar  content  is  apt  to 
be  a  source  of  digestive  disturbances  and  a  frequent  cause  of 
the  failure  of  condensed  milk  as  a  food.  It  may  cause  rickets, 
furunculosis,  anaemia,  etc.  Therefore  it  is  only  to  be  used 
temporarily  during  journeys,  in  the  summer  months,  etc. 

The  second  variety  of  condensed  milk  is  prepared  by  heating 


ARTIFICIAL   FOODS.  331 

milk  for  a  short  time  above  100°  C.  and  then  evaporating  in  a 
vacuum  at  about  60°  C.  to  a  third  of  its  former  volume. 
Monti  has  had  no  good  results  from  its  use. 

Cautley.38  On  account  of  the  excess  of  sugar  present  in 
condensed  milk,  children  fed  on  it  become  fat,  flabby,  and 
anaemic.  Not  enough  proteids  are  present  properly  to  nourish 
the  tissues.  If  no  other  food  is  given,  rickets,  scurvy,  bron- 
chitis, and  gastro-enteritis  may  develop.  It  is  useful  only  as 
a  temporary  food  when  good  cow's  milk  cannot  be  obtained 
or  to  tide  over  an  emergency.  It  is  apt  to  spoil  after  opening, 
it  is  not  always  sterile,  and  the  composition  of  different  brands 
is  apt  to  vary. 

Ashby  and  Wright  2  recommend  its  use  for  short  periods 
of  time,  as  it  is  sterile  and  does  not  curdle  easily.  Too  pro- 
longed use  is  apt  to  produce  scurvy.  It  should  be  diluted  in 
the  proportion  of  one  to  eight  or  one  to  ten.  Only  those  brands 
should  be  selected  which  contain  plenty  of  fat.  Some  contain 
almost  twelve  per  cent.  Clinical  experience  teaches  that  it  is 
sometimes  retained  when  so-called  fresh  milk  is  vomited  or 
gives  rise  to  flatulence  or  colic. 

Starr  133  considers  it  valuable  as  a  temporary  change  of  diet 
when  travelling,  or  when  cow's  milk  cannot  be  obtained.  It 
contains  too  much  cane-sugar  and  not  enough  nutrient  material 
for  the  needs  of  a  growing  baby.  Infants  fed  on  it,  though 
fat,  are  pale,  lethargic,  and  flabby ;  they  possess  little  resistance 
to  disease;  dentition  is  often  delayed  and  rickets  is  likely  to 
result.  If  the  milk  is  kept  too  long,  or  the  packing  has  been 
imperfect,  it  is  liable  to  undergo  decomposition. 

Fenwick  52  makes  the  same  criticisms  as  the  above  and  calls 
attention  to  the  wide  variations  in  the  percentage  of  fat  in 
different  brands,  some  containing  scarcely  any.  He,  too, 
advises  that  it  should  be  used  only  temporarily. 

E.  W.  Saunders  125  points  out  some  of  the  advantages  of  con- 
densed milk  which  probably  explain  its  popularity. 

I.  Bad  milk  cannot  be  condensed,  and  the  large  proportion 


332  THE   ARTIFICIAL   FEEDING   OF   INFANTS. 

of  sugar  serves  to  keep  it,  although  the  bacteria  are  not  de- 
stroyed thereby. 

II.  Practically,  it  is  found  that  condensation  produces 
molecular  changes  in  casein,  which  are  very  advantageous. 
The  curd  produced  by  the  action  of  rennet  or  acids  is  inter- 
mediate in  size  between  that  of  mother's  milk  and  cow's  milk. 

III.  The  fat-globules  are  kept  in  perfect  emulsion,  so  that  it 
is  impossible  to  separate  them  in  the  centrifuge.  Of  course, 
the  fat  is  greatly  deficient  in  amount;  however,  this  small 
amount  of  fat  is  more  available  than  that  of  fresh  milk  because 
of  its  perfect  emulsion  and  from  the  fact  that  the  curd  of  con- 
densed milk,  in  the  meshes  of  which  some  of  the  fat  is  en- 
tangled, is  more  digestible  than  that  of  fresh  milk.  Saunders 
believes  that  condensed  milk  should  never  be  used  for  any 
length  of  time  without  being  fortified  by  cream  or  cod-liver  oil. 
In  addition,  he  makes  a  plea  for  dairy  hygiene,  the  immediate 
cooling  of  fresh  milk,  and  the  maintenance  of  a  low  tempera- 
ture until  it  is  used. 

George  Carpenter  36  declares  that  Swiss  cows  are  more 
subject  to  tuberculosis  than  other  breeds,  the  average  being 
about  eighty-five  per  cent.  Swiss  condensed  milk  is  prepared 
by  evaporating  in  vacuo,  so  that  it  is  not  sterilized.  The  com- 
pleted product  is  therefore  liable  to  contain  tubercle  bacilli  in 
an  active  state. 

Peptonized  Milk. 

Cautley  38  considers  peptonized  milk  valuable  for  tempo- 
rary use  because  of  its  ease  of  digestion.  It  should  not  be 
continued  for  a  long  period,  since  it  does  not  furnish  the 
physiological  stimulus  to  the  natural  secretions.  The  pep- 
tones and  albumoses  which  it  contains  may  cause  diarrhoea. 
A  certain  amount  of  intelligence  is  necessary  for  its  proper 
preparation. 

Ashby  and  Wright.2  Clinical  experience  has  proved  its 
undoubted  value.  Partially  peptonized  milk  curdles  less 
readily  than  raw  milk  and  the  curd  is  softer.    It  must  not  be 


ARTIFICIAL   FOODS.  333 

given  for  too  long  a  period  as  the  sole  food,  lest  scurvy  develop. 
Generally  speaking,  it  is  more  useful  in  gastric  than  in  intes- 
tinal affections. 

Kotch.119  "  Peptonized  milk,  as  a  food  for  the  young  infant, 
consists  of  too  large  an  amount  of  digested  proteids,  too  little 
sugar,  and  a  very  large  over-proportion  of  mineral  matters." 
It  may  be  of  use  to  tide  over  a  period  of  difficulty  until  the 
infant's  stomach  has  recovered  its  digestive  power,  but  the  in- 
dications for  its  employment  may  be  met  by  a  proper  regula- 
tion of  the  proteids  in  the  child's  food  in  a  more  rational  man- 
ner. The  infant's  stomach  is  intended  to  digest  proteids  and 
not  to  have  the  proteids  digested  for  it. 

Starr.133  When  properly  prepared,  peptonized  milk  presents 
great  advantages  in  that  the  necessity  to  use  lime-water,  barley- 
water,  and  other  starchy  attenuants  is  done  away  with.  The 
return  to  the  ordinary  milk  diet  can  be  made  gradually  by 
diminishing  the  time  of  the  artificial  digestion  of  the  milk 
until  pure  milk  can  be  again  used.  It  presents  the  albuminoids 
in  a  minutely  coagulable  and  digestible  form.  It  has  an  alka- 
line reaction,  contains  the  proper  proportion  of  lactose,  salts, 
and  fat,  and  if  only  partially  peptonized  is  not  bitter  to  the 
taste. 

Fenwick  52  thinks  that  its  prolonged  use  results  in  enfeeble  - 
ment  of  the  digestive  organs  of  the  infant,  and  may  lead  to 
anaemia,  rickets,  and  symptoms  allied  to  scurvy. 


APPENDIX. 


A.    Kichmond.    The  composition  of  Peptonized  Milk  (un- 
diluted) is  given  as  follows  by  Vieth: 

Per  cent.  Per  cent. 

Water 89.20  Albumin 0.07 

Fat 3.41  Albumoses 1.88 

Sugar 3.80  Ash 0.68 

Casein 0.96 

Composition  of  Eagle  Brand  Condensed  Milk  (Holt)  : 

Undiluted. 
Per  cent. 

Fat 6.94 

Proteids 8.43 

Sugar 50.69 

Salts 1.39 

Water 31.30 

Composition  of  Swiss,  Austrian,  and  Norwegian  Con- 
densed Milk  (Holt)  : 


Water  and  volatile  substances , 

Salts 

Fats 

Albuminoids 

Lactose 

Cane-sugar 

335~ 


Diluted  with  six 

parts  of  water. 

Per  cent. 

Diluted  with  twelve 

parts  of  water. 

Per  cent. 

0.99 

0.53 

1.20 

0.65 

7.23 

3.90 

0.17 

0.10 

90.49 

94.82 

With  sugar. 
Per  cent. 

Without  sugar. 
Per  cent. 

20.0-30 

46.5-55 

1.5-3 

2.0-3 

8.0-12 

13.0-20 

10.0-13 

13.5-27 

10.0-15 

12.5-18 

30.0-45 

336  APPENDIX. 

Composition  of  Whey  from  forty-six  analyses  by  Konig: 

Per  cent. 

Fat 0.32 

Proteids , 0.86 

Sugar 4.79 

Salts 0.65 

Water 93.38 

Monti's  estimate  is : 

Per  cent. 

Fat 1.00 

_,       . ,    (  Casein 0.03 

Proteids  1 

(  Soluble  albumin 0.80-1.00 

Sugar. .' 4.50-5.00 

Salts 0.70 

Water 


Composition  of  Beef  Juice  (Holt)  : 

Expressed  by  the  warm  process, 

one  pound  gives  two  and 

a  half  ounces. 

Made  by  the  cold  process,  one 

pound,  with  eight  ounces 

water,  gives  eight  and 

a  third  ounces. 

Per  cent. 

Per  cent. 

Fat 0.60 

Proteids 2.90 

3.00 

Extractives 3.40 

1.90 

Water 92.90 

94.90 

Salts 0.20 

0.20 

Composition  of  Beef  Broth  (Holt)  : 

Per  cent. 

Per  cent. 

Proteids 1.02           Salts 

0.88 

Extractives 1.82           Water . . . 

96.28 

APPENDIX.  337 

Composition  of  Barley- Water  (Holt) : 

Per  cent.  Per  cent. 

Proteids 0.09  Starch 1.63 

Fat 0.05  Water 98.20 

Salts 0.03 

Barley- Water  is  made  as  follows.  Add  two  teaspoonfuls 
of  washed  pearl  barley  to  a  pint  of  water;  boil  slowly  down  to 
two-thirds  of  a  pint  and  strain. 

Oatmeal  or  Cracked  Wheat  Water  (Starr). 
Add  one  tablespoonful  of  well-cooked  oatmeal  or  cracked 
wheat  to  a  pint  of  water ;  allow  it  to  simmer  slowly  for  an  hour 
or  two,  stirring  constantly  until  a  smooth  mixture  is  obtained. 
Strain. 

Kice-Water. 
Soak  one  ounce  of  well-washed  rice  in  a  quart  of  water  for 
two  or  three  hours  at  a  moderate  heat;  then  boil  for  an  hour 
and  strain. 

Barley  Jelly  (Starr). 
Put  two  tablespoonfuls  of  barley  flour  into  a  quart  saucepan 
with  one  and  a  half  pints  of  water ;  boil  slowly  down  to  a  pint. 
Strain  and  allow  the  liquid  to  set  into  a  jelly. 

Saw  Beef  Juice  (Warm  Process)  (Starr). 
Take  one  pound  of  sirloin  beef,  warm  it  on  a  broiler  before 
a  quick  fire,  and  cut  into  small  cubes.  Express  the  juice  with 
a  meat  press  or  a  lemon  squeezer.  Bemove  the  fat  that  rises  on 
cooling.  Do  not  actually  cooh  the  meat.  Flavor  with  salt. 
Warm  before  giving,  but  do  not  heat  sufficiently  to  coagulate 
the  albumin. 

22 


338  APPENDIX. 

Saw  Beef  Juice  (Cold  Process)    (Holt). 
Take  one  pound  of  finely  chopped  lean  beef  and  eight  ounces 
of  water,  allow  to  stand  in  a  covered  jar  upon  ice  from  six  to 
twelve  hours;  then  squeeze  out  the  juice  by  twisting  the  meat 
in  coarse  muslin.    Season  with  salt. 


Beef  Broth  (Starr). 
Mince  one  pound  of  lean  beef,  put  it  with  its  juice  into  an 
earthen  vessel  containing  a  pint  of  water  at  85°  F.,  and  let  it 
stand  for  one  hour.  Strain  through  stout  muslin,  squeezing 
all  the  juice  from  the  meat.  Place  this  liquid  on  the  fire  and, 
while  stirring  briskly,  heat  slowly  just  to  the  boiling  point; 
then  remove  at  once  and  season  with  salt. 

Mutton  Broth  (Starr). 
Add  one  pound  of  loin  of  mutton  to  three  pints  of  water. 
Boil  gently  until  very  tender,  adding  a  little  salt;   strain  into 
a  basin,  and  when  cold  skim  off  the  fat.    Warm  when  serving. 

Chicken  Broth  (Starr). 
A  small  chicken  or  half  of  a  large  fowl,  thoroughly  cleaned 
and  with  all  the  skin  and  fat  removed,  is  to  be  chopped,  bones 
and  all,  into  small  pieces.  Put  them  with  salt  into  a  small 
saucepan  and  add  a  quart  of  boiling  water;  cover  closely  and 
simmer  over  a  slow  fire  for  two  hours.  After  removing,  allow 
it  to  stand,  still  covered,  for  an  hour;  then  strain  through  a 
sieve. 

Veal  Broth  (Starr). 

Mince  from  one-half  to  one  pound  of  lean  veal  and  pour 

upon  it  a  pint  of  cold  water.     Let  it  stand  for  three  hours, 

then  slowly  heat  to  the  boiling  point.    After  boiling  briskly  for 

two  minutes,  strain  through  a  fine  sieve  and  season  with  salt. 


APPENDIX.  339 

Egg-Water. 

Add  the  white  of  one  egg  and  a  pinch  of  salt  to  six  ounces 
of  cold  water  and  mix  thoroughly.  This  will  be  more  palatable 
if  sweetened. 

Dextrinized  Gruel  (Chapin). 

To  one  pint  of  gruel  (made  by  boiling  for  fifteen  minutes 
one  tablespoonful  of  wheat,  oatmeal,  or  barley  flour  with  one 
and  a  half  pints  of  water)  add,  when  cool  enough  to  be  tasted, 
one  teaspoonful  of  diastase  or  "  Cereo"  or  of  a  thick  malt 
extract.  This  mixture  should  be  kept  at  a  temperature  of 
150°  F.  for  from  fifteen  to  twenty  minutes,  until  the  gruel 
becomes  thin  and  watery.  The  conversion  of  starch  into  dextrin 
and  maltose  will  then  be  complete. 

Peptonized  Milk. 

1.  Eapid  method.  Take  half  a  pint  of  milk,  half  a  pint  of 
water,  two  ounces  of  cream,  and  one  measure  of  peptogenic 
milk-powder.  Place  on  the  range  and  bring  to  a  boil  in  ten 
minutes.  This  should  be  cooled  and  kept  in  the  refrigerator 
until  used. 

2.  Use  the  same  quantities  as  above  and  place  the  mixture 
on  the  back  of  the  range  or  in  water  of  a  temperature  of  115° 
F.  for  thirty  minutes;  then  remove  and  put  on  ice  or  else  bring 
the  mixture  quickly  to  the  boiling  point  to  destroy  the  activity 
of  the  digestive  ferments. 

3.  If  the  same  process  as  No.  2  is  carried  out  for  two  hours 
the  conversion  of  the  casein  into  albumoses  and  peptones  will 
be  complete.  (One  measure  or  capful  of  peptogenic  milk- 
powder  must  be  added  for  each  pint  of  the  mixture  prepared.) 

Peptogenic  milk-powder  consists  of  sodium  bicarbonate,  pan- 
creatin,  and  milk-sugar. 

Liebig's  Food  (Leeds). 
Take  equal  parts  of  wheat  flour  and  barley  malt,  to  which 
a  certain  amount  of  wheat  bran  is  added  (on  account  of  the 


340  APPENDIX. 

phosphates  and  nitrogenous  matter  it  contains).  One  per  cent, 
of  potassium  bicarbonate  is  also  added,  and  the  whole  is  stirred 
with  enough  water  to  make  a  thin  paste.  It  is  then  allowed 
to  stand  for  several  hours  and  heated  to  150°  F.  until  the 
conversion  of  the  starch  into  maltose  and  dextrin  is  completed. 
The  strained  residue  is  then  pressed  and  exhausted  with  warm 
water.  The  extract  is  evaporated  and  dried  into  a  powdery 
mass. 

Liebig's  Soup  (Monti). 

Twenty  cubic  centimetres  of  wheat  flour  are  mixed  cold 
with  two  hundred  cubic  centimetres  of  unskimmed  milk.  The 
meal  must  be  thoroughly  mixed  and  heated  over  a  slow  fire 
(Mixture  No.  1). 

Twenty  cubic  centimetres  of  malted  barley  are  mixed  with 
forty  cubic  centimetres  of  a  one  per  cent,  solution  of  potassium 
carbonate.  This  is  left  standing  for  half  an  hour,  and  then  mixed 
with  No.  1.  After  stirring  for  fifteen  minutes  it  is  heated  to 
boiling  and  then  strained.  On  account  of  the  starch,  it  cannot 
be  used  before  the  fifth  month.  Children  fed  on  it  are  subject 
to  rickets,  etc.  It  can,  however,  be  added  to  the  nourishment 
in  the  case  of  older  infants  when  the  supply  of  mother's  milk 
is  insufficient.    It  can  also  be  used  in  weaning. 

Scraped  Meat. 
Take  a  piece  of  raw  juicy  steak  and  scrape  away  the  pulp  of 
the  meat  with  a  dull  knife  or  a  piece  of  glass.  Place  this  meat 
pulp  (as  much  as  is  needed)  on  a  piece  of  toast  or  stale  bread 
and  bake  in  the  oven  for  five  minutes.  Flavor  with  salt  and  a 
small  amount  of  butter.  It  can  be  administered  either  with 
or  without  the  toast. 

Oat  Jelly  (Kotoh). 
Two  ounces  of  coarse  oatmeal  are  soaked  in  a  quart  of  cold 
water  for  twelve  hours.     The  mixture  is  then  boiled  down  so 


APPENDIX.  341 

as  to  make  a  pint  and  strained  while  hot.    On  cooling,  a  jelly 
is  formed.    Keep  on  ice  until  needed. 

B.  Henry  Leffmann.  Methods  of  Milk  Analysis. — For 
the  determination  of  the  proteids  in  milk  two  methods  are 
in  common  use,  termed  respectively  the  Ritthausen  and  the 
Kjeldahl  method.  Each  has  been  modified  in  details  by  differ- 
ent analysts.  The  Ritthausen  method  depends  on  the  precipi- 
tation of  the  proteid  matter  by  a  copper  salt  and  subsequent 
weighing  of  the  curd  so  obtained,  with  due  allowance  for  the 
fat  and  mineral  matter  that  may  be  present.  The  Kjeldahl 
method  depends  on  the  conversion  of  the  nitrogen  into  ammo- 
nium compounds  and  subsequent  estimation  of  the  ammonium. 
The  amount  of  proteids  is  calculated  by  the  use  of  the  factor 
based  upon  the  analysis  of  the  different  proteid  matters.  The 
Ritthausen  method  is  subject  to  errors,  most  of  which  tend  to 
increase  the  figures  for  the  proteids.  The  Kjeldahl  method  is 
also  subject  to  errors,  some  of  which  tend  to  diminish  the 
figure  for  the  proteids ;  but  the  principal  errors  in  this  method 
are  that  any  non-proteid  nitrogen  (that  is,  the  so-called  ex- 
tractives) is  counted  as  proteid;  secondly  and  more  seriously, 
the  factor  for  calculation  is  uncertain,  as  it  differs  with  each 
form  of  proteid.  American  chemists  usually  employ  6.25  for 
cow's  milk  proteid;  some  prominent  English  chemists  use 
6.33.    A  factor  as  high  as  6.67  has  been  recommended. 

C.  A  Clinical  Method  for  the  Estimation  of  Breast-Milk 
Proteids. 
George  Woodward.149  Ten  cubic  centimetres  of  the  milk 
to  be  tested  are  placed  in  two  glass  burettes  (five  cubic  centi- 
metres in  each)  constructed  with  a  glass  pinchcock  at  the  lower 
end  to  facilitate  drawing  off  the  serum.  The  burettes  are  then 
placed  in  a  warm  spot  (from  95°  to  100°  F.)  to  favor  fer- 
mentation. The  time  required  to  obtain  distinct  precipitation 
of  the  casein  is  from  eighteen  to  twenty-four  hours.     When 


342  APPENDIX. 

the  cream  has  fully  separated  as  a  solid  yellow  layer,  the 
burettes  are  placed  in  cold  water  to  increase  the  viscosity  of 
the  cream  and  from  each  the  five  cubic  centimetres  of  serum 
are  drawn  into  fifteen-cubic-centimetre  graduated  centrifu- 
gating  tubes,  leaving  the  cream  in  situ.  The  tubes  are  then 
filled  to  the  fifteen-cubic-centimetre  mark  with  Esbach  solution 
(picric  acid  five  grammes,  citric  acid  ten  grammes,  water  five 
hundred  cubic  centimetres). 

The  mixture  is  stirred  with  a  glass  rod  and  then  revolved 
in  a  hand  centrifuge  until  a  constant  reading  is  obtained. 
The  estimates  from  the  two  tubes  are  taken  and  a  mean  derived 
from  the  sum  of  these.  By  a  Kjeldahl  control  Woodward 
found  this  method  to  be  fairly  exact. 

Leffmann-Beam  Method  for  the  Estimation  of  Fat. 

D.  The  Leffmann-Beam  method  257  for  the  estimation  of 
the  fat  in  milk  or  cream  requires  a  specially  constructed  cen- 
trifugal machine  and  test-bottles  with  a  capacity  of  thirty  cubic 
centimetres,  provided  with  a  graduated  neck,  each  division  of 
which  represents  one-tenth  per  cent,  by  weight  of  butter  fat. 

"  Fifteen  cubic  centimetres  of  the  milk  are  measured  into 
the  bottle,  three  cubic  centimetres  of  a  mixture  of  equal  parts 
of  amyl  alcohol  and  strong  hydrochloric  acid  added,  mixed, 
the  bottle  filled  nearly  to  the  neck  with  concentrated  sulphuric 
acid,  and  the  liquids  mixed  by  holding  the  bottle  by  the  neck 
and  giving  it  a  gyratory  motion.  The  neck  is  now  filled  to 
about  the  zero  point  with  a  mixture  of  sulphuric  acid  and 
water  prepared  at  the  time.  It  is  then  placed  in  the  centrifu- 
gal machine,  which  is  so  arranged  that  when  at  rest  the  bottles 
are  in  a  vertical  position.  If  only  one  test  is  to  be  made,  the 
equilibrium  of  the  machine  is  maintained  by  means  of  a  test- 
bottle  or  bottles  filled  with  a  mixture  of  equal  parts  of  sul- 
phuric acid  and  water.  After  rotation  from  one  to  two  min- 
utes, the  fat  will  collect  in  the  neck  of  the  bottle  and  the 
percentage  may  be  read  off.    It  is  convenient  to  use  a  pair  of 


APPENDIX.  343 

dividers  in  making  the  reading.  The  legs  of  these  are  placed 
at  the  upper  and  lower  limits  respectively  of  the  fat,  making 
allowance  for  the  meniscus;  one  leg  is  then  placed  at  the  zero 
point  and.  the  reading  made  with  the  other.  The  results  do 
not  vary  from  those  obtained  by  the  Adams  process  by  more 
than  one-tenth  per  cent,  and  are  generally  even  closer. 

"  Cream  is  to  be  diluted  to  exactly  ten  times  its  volume,  the 
specific  gravity  taken,  and  the  liquid  treated  as  a  milk.  Since 
in  the  graduation  of  the  test-bottles  a  specific  gravity  of  1030 
is  assumed,  the  reading  must  be  increased  in  proportion. 

"A  more  accurate  result  may  be  obtained  by  weighing  in 
the  test-bottle  about  two  cubic  centimetres  of  the  cream  and 
diluting  to  about  fifteen  cubic  centimetres.  The  reading  ob- 
tained is  to  be  multiplied  by  15.45  and  divided  by  the  weight 
in  grammes  of  cream  taken." 

Modification  of  the  Lejfmann-Beam  Method.197 
A  specially  constructed  graduated  milk-bottle  is  required 
which  will  fit  into  any  centrifuge  used  for  urinalysis,  etc. 
Five  cubic  centimetres  of  milk  are  introduced  into  the  milk- 
bottle  through  a  small  pipette;  one  cubic  centimetre  of 
Eeagent  No.  1  is  added,  and  the  bottle  well  shaken.  (Eeagent 
No.  1 :  fusel  oil  thirty-seven  parts  by  volume,  wood  alcohol 
thirteen  parts,  hydrochloric  acid  fifty  parts.)  Eeagent  No.  2 
(sulphuric  acid  of  a  specific  gravity  of  1832)  is  added  little 
by  little  with  constant  agitation  until  the  bottle  is  filled  to  the 
base  of  the  graduated  neck.  A  mixture  of  equal  parts  of  sul- 
phuric acid  and  water  is  then  added  to  reach  a  little  above  the 
highest  (or  first)  graduation  mark.  The  bottle  is  then  whirled 
in  the  centrifuge  for  two  minutes ;  the  fat  will  then  have  risen 
in  a  clear  yellowish  layer  which  can  be  read  in  percentages 
from  the  scale  on  the  neck  of  the  bottle.  If  the  milk  be  richer 
than  five  per  cent,  of  fat,  dilute  equally  with  water.  In  testing 
cream,  mix  five  parts  of  cream  with  twenty  parts  of  water. 
The  result  should  be  multiplied  by  five. 


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260.  Ravenel,  M.  P.     Journal  of  Comparative  Medicine  and  Veteri- 

nary Archives,  April,  1898. 

261.  Koch,  Robert.    Address  at  the  British  Congress  on  Tuberculosis, 

Lancet,  July  23,  1901. 


INDEX. 


Absorption,  gastric,  69,  70,  73,  92 

intestinal,  82,  83,  92 
Acid,  acetic,  73,  87,  88 

butyric,  73,  87,  88 

hydrochloric,  68,  70-77,  197 

lactic,  55,  69-75,  77,  82,  87,  88 

valeric,  87,  88 
Acidity,  best  means  to  overcome,  130,  162,  166 
Acids,  fatty,  82,  88 
Adriance,  19,  21,  25,  31,  271 
Alcohol,  176 

Alkaloids  in  cow's  milk,  215 
Amido-acids,  82,  83 
Anabolic  ratio,  258 
Annotto,  180 
Armstrong,  John,  9 
Arrowroot- water,  13,  118 
Artificial  digestion,  experiments  in,  84,  85 
raw  and  sterilized  milk,  234,  235 
Ass's  milk,  9,  10,  44 

B 

Backhaus,  198 

Milk,  99,  103,  108 
Bacteria,  action  of,  on  starch,  214 
on  sugar,  214 
as  agents  of  fermentation,  212 

of  putrefaction,  213 
in  cow's  milk,  181,  182,  191 
anaerobic,  205,  206 
color-producing,  208 
lactic  acid,  201,  202 
lactic  vs.  peptonizing,  207 
peptonizing,  204-207 


355 


356  INDEX. 

Bacteria  in  cow's  milk,  peptonizing  spores,  204,  205. 
saprophytic,  200 
thermal  death-point  of,  219,  220 
thermophile,  206 

in  faeces,  197 

in  intestinal  digestion,  81,  83,  211-213 

in  meconium,  197 

in  mother's  milk,  199 

in  stomach,  197 

rapidity  of  growth  of,  198 
Baner,  William  L.,  300 
Bang,  219 
Barley  jelly,  337 

water,  composition  and  preparation  of,  337 
Bauer  and  Deutsch,  72-74 
Beef  juice,  172,  175,  291,  292,  336-338. 
Beef  peptonoids,  175,  291,  292 
Bendix,  99,  169 
Biedert,  25,  26,  94,  212 
Biedert's  Cream  Conserve,  95,  96,  105. 

Mixture,  95,  105,  267,  268 
Bile,  80,  81,  90 
Blackader,  220,  221 
Blauberg,  27,  88,  266 
Boiling  milk,  231 

objections  to,  232 
Boissard,  118 
Bonwill,  324 

Bottled  milk,  dangers  of,  180 
Bread  and  butter,  173 
Broths,  9-11,  172,  175,  291,  292,  338 
Budin,  118 
Buttermilk,  113,  285 


Calories,  115,  258,  260,  261 

Calorimetric  method  of  feeding,  96-99 

Carstens,  228 

Carter  and  Richmond,  29 

Cattle,  best  breeds  of,  for  dairy  purposes,  186 

feeding  of,  188 
Cautley,  163,  186,  188,  242,  250,  273,  327 


INDEX.  357 

Centrifugal  cream,  advantages  of,  144,  150,  287,  288 

objections  to,  107,  117,  158 
Centrifugation,  effect  of,  on  bacterial  content,  60 

on  fat  emulsion,  149,  150,  157,  158 
Cereal  coffee,  176 
Certified  milk,  49,  185,  276 
Chapin,  H.  Dwight,  158,  310 
Chapin's  dipper,  311 
Chicken  in  infant's  diet,  175 
Cholesterin,  80,  81,  86,  90 
Chyme,  68 
Clarke,  John,  10 

Coagulation  of  cow's  milk,  effect  of  acids  on,  66 
of  fat  on,  68 

of  heat  on,  52,  85,  220,  221 
of  starch  on,  10,  159,  163 
of  whey  on,  106,  107 
Cocoa,  176 
Cod-liver  oil,  59,  164 
Coffee  as  a  stimulant,  176 
Cohn,  73 

Coit,  Henry  L.,  184,  300 
Collins,  H.  Johnson,  209 
Comby,  118,  168 

Commercial  cream,  dangers  of,  288,  298 
Condensed  milk,  286,  315,  316,  330-332 

composition  of,  335 
Conn,  H.  W.,  202,  210 
Conradi,  221 

Constituents  of  average  diet  for  infant  six  months  old,  256 
Coriat,  J.  H.,  84 
Cow's  milk,  albumose  in,  51 
ash  in,  56 

average  composition  of,  46-49 
casein,  50,  52,  53 

affinity  of,  for  calcium  salts,  52,  56 
ferments  in,  204 
coagulation  of,  56,  68 
forms  of,  66,  67 

of,  compared  with  mother's  milk,  68,  282 
with  acetic  acid,  54  • 

colostrum  in,  46,  47 


358  INDEX. 

Cow's  milk,  contamination  of,  179-182,  200 

description  of,  46 

English  standard,  47 

fat  in,  54,  55 

fermentation  of  sugar  in,  55 

nitration  of,  60 

gases  in,  59 

impurities  in,  201 

inspection  of,  193 

iron  in,  56 

lactalbumin  in,  50,  52,  53 

lacto-globulin  in,  51,  52 

lecithin  in,  55,  57,  58 

nucleon  in,  57,  58 

ordinary  method  of  handling,  179 

phosphates  in,  58 

phosphorus  in,  53,  57-59 

produced  by  different  breeds  of  cattle,  48 

proportions  of  albuminoids  in,  52 

reaction,  44 

salts  in,  56-58 

specific  gravity  of,  44,  45 

Storches'  mucoid-proteid  in,  51 

strippings,  50 

sugar  in,  55 

sulphur  in,  53 

total  acidity  of,  104 

variations  in  composition  of,  46,  47,  49,  60 
Crandall,  Floyd  M.,  160 
Cream  mixtures,  10,  299,  300 

with  condensed  milk,  317 
necessity  for,  14 

percentage  composition  of,  155,  299 
raising,  effect  of  temperature  on,  314 
thickener,  180,  181 
Cuthbert,  Walter  M.,  312 
Czerny,  114 


Dairy  farm  regulations,  183,  187,  188,  189-193 

in  Denmark,  192 
Defecation,  85 


INDEX.  359 


Dextrinized  gruels,  159,  160,  164,  339 
Diastase,  decoctions  of,  159 
Diet  during  second  year  of  infancy,  174-178 
Digestion,  61 

gastric,  62,  65,  69,  70,  76,  77 

intestinal,  78,  81 

summary  of,  84 
Digestive  equilibrium,  154 

ferments,  61,  66,  68,  75,  80,  81 
Dilution,  dangers  of,  114 
Douglass,  Carstairs,  223 
Drews,  330      > 
Duclaux,  205 

E 

Eberle,  197 

Edlefsen,  57 

Edsall,  60 

Egg  albumin,  158,  160,  175,  291 

Egg-water,  339 

Egg-yolk,  160,  166,  172 

Enzymes,  diastatic,  81,  82 

fat-splitting,  82 

intestinal,  84,  90,  214 

saccharifying,  82 

vegetable,  85 
Escherich,  212,  213 
Estes,  181 
Excretion,  85 

F 

Faeces,  amount  of,  87 
analyses  of,  87-90 
bacteria  in,  88,  90 
casein  flakes  in,  87,  91 
color  of,  87,  88,  91 
examination  of,  91,  92 
fat  percentage  of,  89 
ferments  of,  90 

from  a  diet  of  cow's  milk,  90,  91 
from  a  diet  of  mother's  milk,  91 
mucus  in,  90,  91 
nucleins  in,  90,  91 


360  INDEX. 

Faeces,  pigment  of,  87 

reaction  of,  87,  88,  91 

toxicity  of,  88 

urobilin  in,  87 
Fat,  effect  of  ferments  on,  82 

emulsion  of,  83 

emulsions,  effect  of  transportation  on,  157 

in  barley-water,  whey,  gravity  and  centrifugal  cream  mix- 
tures, 157 

proper  proportion  of,  285-287 

saponification  of,  83 
Fat  diarrhoea,  95,  121,  253 
Feeding  of  difficult  cases,  137-139,  155,  156,  284,  285 

size  of  meals,  65,  97,  281 
Feeding-bottles,  12,  321 
Feer,  97 

Fenwick,  W.  Soltau,  61,  75,  164 
Filatow,  113 

Filtration  through  cotton,  235,  236  • 

Fischer,  Louis,  161 
Fliigge,  205 
Frank,  J.  P.,  9 
Freeman,  R.  G.,  217,  218 
Freezing  of  milk,  233 
Fruit,  174 


Gaertner's  Milk,  99,  103,  109,  110 
Gastric  fermentation,  77 

juice,  antiseptic  action  of,  212 

chemistry  of,  70-77 

reaction  of,  66 
Gerhardt,  Carl,  13 
Gernsheim,  227,  228 
Getty,  222 

Gittings's  dipper,  313 
Goat's  milk,  44 
Gregor,  112 

Gregor's  Malt  Soup,  112 
Griffith,  J.  P.  Crozer,  244 
Growth  during  infancy  (see  Weight  and  Growth) 


INDEX.  361 

H 


Hamilton,  303 

Harrington,  50 

Hay  em  and'  Winter,  70 

Henoch,  100 

Heubner,  25,  96,  97 

Heubner's  Mixture,  96,  97,  104,  151,  267 

Hoffmann's  analyses,  27 

Holt,  128,  169,  174 

Holt's  weekly  report,  325 

Home  modification,  131,  147,  148,  158,  296 

Huddleston,  194 

Hygiene  in  infant  feeding,  importance  of,  99,  101,  140 


Importance  of  a  pure  milk  supply,  196,  197,  216 

of  fresh  cream,  196 
Inadequate  nursing,  symptoms  of,  135,  136 
Indigestion,  symptoms  of,  135,  136 
Individualization,  necessity  for,  96,  99-101,  277 
Indol,  83,  88 

Intervals  between  feedings,  281,  323 
Intestinal  fermentation,  81,  213 

gases,  89 

putrefaction,  83,  84,  87 

reaction,  213 
Intestine,  anatomy  of,  78,  79,  85,  86 
Intoxications  through  milk,  214,  215 
Iron  in  metabolism,  253-255 


Jacobi,  119,  174 
Johannessen,  25,  40 


Kalischer,  207 

Keller,  Arthur,  114,  253 

Klimmer,  187,  205 


K 


362  INDEX. 

Koch,  Robert,  210 
Koeppe,  39 
Konig,  27 
Koplik,  151,  152 
Krauss,  330 


Laboratory  milk,  128,  150,  158,  279,  280 

objections  to,  12G-128,  161 
Lactase,  55,  69,  81,  82 
Lactic  acid  fermentation,  69,  82,  212 
Lactic  ferments  in  cow's  milk,  201 
Lactose,  69,  82,  156,  164 
Lahmann's  Vegetable  Milk,  103,  108 
Langermann,  197 
Lecithin,  90,  256 
Leeds,  18,  30,  39,  160 
Leffmann,  Henry,  341 
Leffmann-Beam  method  of  fat  analysis,  342 

modified,  343 
Lehmann,  27 
Liebig's  food,  339 

soup,  340 
Lime  salts  in  metabolism,  255,  289 
Lime-water,  292 
Lipase,  82 
Loeflund's  Cream  Conserve,  103,  109 

Peptonized  Milk,  109 

M 

Malt  extract,  176 

soup,  112,  265 
Maltose,  115,  264 
Marcel  and  Labbg,  70 
Mare's  milk,  44 
Marfan,  A.  B.,  116,  200,  259 
Marfan's  Mixture,  105 
Mathematical  formulae  for  modification:    Coit,  300;    Baner,  300,  301; 

Hamilton,  303;    Westcott,  301-303,  305-309 
Meconium,  80,  81,  86,  197 


INDEX.  363 

Meigs,  Arthur  V.,  15,  25 
Meigs's,  Arthur  V.,  Mixture,  15,  16,  17,  153 
Meigs,  J.  Forsyth,  13 
Meigs's,  J.  Forsyth,  Mixture,  13,  296 
Metabolic  ratio,  258 
Metabolism,  58,  250 
experiments,  266 
mineral  salts  in,  266 
Method  of  calculating  percentages  without  formulae,  306,  307,  326 
Methods  of  feeding:    whole  milk,  277;    moderate  dilutions,  278;    high 
dilutions,  278;    top-milk  mixtures,  279,  287;    whey  mixtures, 
279 ;    laboratory  milk,  279,  280 
of  infant  feeding:    Biedert,  94,  95;    Heubner,  96;    Henoch,  100; 
Baginsky,  100;    Monti,  103;    Filatow,  113;    Marfan,  116;    Ja- 
cobi,    119;     Starr,    124;     Holt,   128;     Rotch,   139;     Ashby  and 
Wright,  161;    Cautley,  163;    Fenwick,  165 
of  milk  analysis,  341,  342 
Michel,  Charles,  234 
Milk  commissions,  184,  185 
Milk-laboratory,  130,  143-147 
Miller,  D.  J.  M.,  174 
Miquel,  197 
Mixed  feeding,  168 

milk,  45 
Monti,  Alois,  35,  103,  176,  187 
Monti's  Whey-Milk  Mixture,  103,  105,  107 
Morse,  J.  L.,  110 

Mother's  milk:  acidity,  104;  amount  secreted,  33;  ash,  56;  at  dif- 
ferent times  of  lactation,  26,  30-33;  bacteria  in,  198,  200;  before 
and  after  suckling,  39,  40;  calories  per  litre,  32;  casein,  23,  24, 
27;  coagulation,  24,  68;  colostrum,  20-22;  composition,  22,  23, 
26-32,  34,  41;  description,  18;  effect  of  menstruation,  168,  169; 
effect  of  pregnancy,  168,  169;  effect  of  infectious  diseases,  168,  169; 
estimation  of  proteids,  14,  15,  19,  24-28,  30,  35;  extractives,  25,  29; 
fat,  32,  35-37;  fat-globules,  35,  36;  in  premature  confinements, 
272;  lecithin,  38,  39,  57,  58;  mean  composition,  41;  nitrogen 
present,  32;  nucleon,  38,  57,  58;  phosphorus,  23,  38,  39,  43,  57; 
ratio  of  casein  to  albumin,  24,  27,  42;  ratio  of  nitrogenous  to  non- 
nitrogenous  substances,  33,  43;  reaction,  20;  salts,  37,  38,  57,  58; 
soluble  albumin,  23,  24,  42;  specific  gravity,  18,  19,  31;  sugar,  37; 
summary,  40-42;  value  of  constituents,  269;  variations  in  general 
composition,  27,  29-33 


364  INDEX. 

N 

Necessity  for  fat,  251,  252,  298 

for  heat-producing  food,  250 

for  proteid,  251 

for  salts,  253 

for  sugar,  253 

for  water,  10,  122,  176,  250,  257,  325 
Needs   (alimentary)  of  infant  at  different  ages,  262 
Nitrogen  metabolism,  263,  264 
Northrup,  150 

o 

Oat  jelly,  340 
Oatmeal-water,  337 
Overfeeding,  65 

P 

Palmer,  George  T.,  193 
Panada,  9 

Pancreatic  secretion,  66,  80 
Paracasein,  67,  68 
Paranuclein,  58,  69 
Parotid  gland,  61,  62 
Pasteurization,  158,  217-220 

alterations  produced  by,  218 

cheap  method  of,  222,  223 

objections  to,  223,  224 
Pepsin,  66,  75,  76 
Peptone,  66,  69,  76,  78,  88,  175 
Peptonized  milk,  156,  162,  283,  284,  291,  332,  333,  339 

composition  of,  335 
Percentage  system,  128 
Peristalsis,  62,  77,  85,  86 
Peters,  191 
Pfeiffer,  Emil,  26 

Phosphorus  in  metabolism,  255,  265,  289 
Plasmon,  324 

Premature  infants,  feeding  of,  270-274 
milk  modification  for,  272,  274 
weight  of,  273 
Preservatives,  195 
Principles  of  infant  feeding,  275 


INDEX.  365 

Proprietary  foods:    analyses,  328;    classification,  327;    indications  for 

use,  329,  330;    use  of,  166,  175,  317,  327 
Proteids,  proper  proportion  of,  14,  15,  129,  154,  282-284 
Pseudonuclein,  69 
Ptyalin,  61,  80 
Pus  in  milk,  181,  182,  199,  200 


Ratio  of  nitrogenous  to  non-nitrogenous  elements  in  the  diet,  116,  286 

Ravenel,  219 

Relative  value  of  milk  constituents,  257 

Rennet,  85 

Rennin,  84,  85 

experiments  with,  85,  159 
Rice-water,  337 

Richmond,  H.  Droop,  29,  46,  257 
Rickets,  228,  229,  252 

phosphorus  in,  59 
Rieth's  Albumose  Milk,  103,  110 
Rotch,  T.  M.,  33,  34,  139,  187 
Rudisch,  J.,  175 
Rules  for  varying  milk  percentages,  135,  136,  323-325 


s 

Salge,  113 

Saliva,  diastatic  action  of,  61,  62 

Salivary  glands,  61,  62 

Salol  test,  76 

Salts,  288 

Saunders,  E.  W.,  331 

Schill,  197 

Schlesinger,  114 

Schlossmann,  31,  32,  106 

Schmid-Monnard,  115 

Schniirer,  Joseph,  66 

Scraped  meat,  172,  175,  340 

Scurvy,  59,  99,  118,  127,  227-229 

Sedgewick  and  Batchelder,  198 

Seifert,  100 

Separated  milk,  59,  60 


366  INDEX. 

Skatol,  83,  88 
Skimmed  milk,  59 
Smith,  Theobald,  220 
Sodium  carbonate,  107 

chloride,  123,  254,  289 
Soldner,  28 
Somatose,  175,  330 
Sonnenberger,  214 
Soxhlet,  224 
Spasmotoxin,  208 
Ssnitkin's  rule,  142 
Standard  milk,  184,  185 
Starch,  103,  171,  174,  289,  290 
digestion,  61,  62,  80,  141 
excess  of,  120,  171 
Starchy  diluents,  11,  129,  157,  159 
Starr,  Louis,  124 
Steapsin,  80,  83 
Steffen's  Veal  Broth,  111 

Sterilization,  216,  217,  224,  226,  276,  293-295 
changes  caused  by,  225-227,  229-233 
destroys  enzymes,  221 
fractional,  224 
in  open  vessels,  220 
objections  to,  228 
Sterilized  milk,  dangers  of,  205,  207,  216,  217,  232 

taste  of,  59 
Stoklasa,  38 
Stomach,  anatomy  of  the,  62,  77 

bacterial  content  of  the,  76,  197 
capacity  of  the,  62-65,  143 
dilatation  of  the,  63,  65,  122 
time  of  evacuation  of  the,  62,  63,  115 
Stools,  healthy,  86,  87 
number  of,  86 
pathological,  93 
Storches'  mucoid-proteid,  51 
Strippings,  50 
Submaxillary  glands,  61 
Substitutes  for  milk,  160 
Sugar,  proper  proportion  of,  129,  288 
Sugar  solution,  preparation  of,  129,  297 


INDEX.  367 

T 

Tables  of  feeding:    Feer,  97;    Baginsky,  102;    Starr,  125;    Holt,  131; 

Rotch,  142,  149;    Cautley,  163,  164;    Fenwick,  165;    authors',  322 
Taylor  and  Wells,  169,  187 
Thiemich  and  Papiewsky,  110 
Thomson,  John,  166 
Thorner,  59 
Top  milk,  287 

analyses,  132,  153,  158,  161,  310,  312-314 

mixtures,  133,  134,  158,  161,  310 
Townsend,  C.  W.,  158 
Toxins  in  milk,  215 

Transmission  of  infectious  diseases  by  milk,  182,  208,  209,  211 
Troitsky,  221 
Trypsin,  80,  81,  82 
Tubercular  infection  from  cow's  milk,  209 

from  mother's  milk,  209 
Tyrotoxicon,  208 

u 

Uffelmann,  87-89 
Urea  elimination,  262 


V 

Variot,  226,  227 

Vegetables,  173 

Vigier's  Humanized  Milk,  105 

Voltmer's  Mother's  Milk,  103,  109 

Von  Puteren,  197 

Von  Ranke,  44 

Von  Starck,  228 

Voorhees,  Edward  B.,  194 

Voorhees,  James  D.,  270 


w 

Warthin,  A.  S.,  84 

Weaning,  indications  for,  167-169 

method  of,  170 

time  of,  167,  168 


368  INDEX. 

Weber,  205 

Wegscheider,  88 

Weight,  115,  152,  237,  259,  260 

charts,  244,  245,  248,  249 

gain  in,  238-243,  293 

in  mixed  feeding,  241 

generalizing  method,  244 

importance  of  recording,  249,  293 

individualizing  method,  244 
Westcott,  T.  S.,  154,  301 
Whey,  67,  162,  290 

analysis,  305,  336 

preparation  of,  305,  336 
Whey-cream  mixture,  curdling  of,  157 

mixtures,  155-157,  162,  290,  305 
White  and  Ladd,  156 
Whole  milk,  use  of,  114,  118 
Winters,  Joseph  C,  153 
Wittmaack,  38 
Wolf  and  Friedjung,  73 
Woodward,  George,  22 


Yeasts  in  cow's  milk,  208 


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